CVE-2026-47321
Apache MINA: Unbounded Decompression Amplification DoS in Zlib.inflate
The CompressionFilter class uses ZLib to deflate and inflate data sent and received. When we inflate incoming data, the filter does not control the resulting size, and create a buffer no matter what.
Some compressed data may have a compression ration greater than 1 thousand, leading to an exhaustion of the application memory, as we don't control the deflated size.
The fix adds such a control by allowing the application developer to provide a fixed size limit, which when reached throws an exception. It also allows the user to provide a compression ratio that should not be exceeded, protected the application from small inflated files that inflate in gigantic files, but with a grace limit for the resulting size (1Mb) to avoid false positive (like a very small file inflating with a high ratio, but resulting with a acceptable size, like a few thousands bytes)
For application using this feature, it is highly recommended to create the CompressionFilter and to pass the maximum limit as a forth constructor parameter, maxDecompressedSize:
public CompressionFilter(final boolean compressInbound, final boolean compressOutbound, final int compressionLevel, final int maxDecompressedSize)Optionally one can also provide a maxDecompressRatio fifth parameter, and a decompressRatioMinSize sixth parameter to allow small inflated files with a high compression ratio to still be accepted.
Here are the additional constructor:
public CompressionFilter(final boolean compressInbound, final boolean compressOutbound,
final int compressionLevel, final int maxDecompressedSize,
final long maxDecompressRatio, final long decompressRatioMinSize)
Also note that a fluent API has been added to spare the users the pain to call a constructor with that many parameters:
CompressionFilter compressionFilter = new CompressionFilter()
.setCompressionLevel(Zlib.COMPRESSION_MAX)
.setMaxDecompressedSize(1_000_000)
.setMaxDecompressRatio(100).
.setDecompressRatioMinSize(100_000);
Applications using Apache MINA are advised to upgrade and configure their CompressionFilter instance.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
7.5
Apache MINA: Unbounded Decompression Amplification DoS in Zlib.inflate
The CompressionFilter class uses ZLib to deflate and inflate data sent and received. When we inflate incoming data, the filter does not control the resulting size, and create a buffer no matter what.
Some compressed data may have a compression ration greater than 1 thousand, leading to an exhaustion of the application memory, as we don't control the deflated size.
The fix adds such a control by allowing the application developer to provide a fixed size limit, which when reached throws an exception. It also allows the user to provide a compression ratio that should not be exceeded, protected the application from small inflated files that inflate in gigantic files, but with a grace limit for the resulting size (1Mb) to avoid false positive (like a very small file inflating with a high ratio, but resulting with a acceptable size, like a few thousands bytes)
For application using this feature, it is highly recommended to create the CompressionFilter and to pass the maximum limit as a forth constructor parameter, maxDecompressedSize:
public CompressionFilter(final boolean compressInbound, final boolean compressOutbound, final int compressionLevel, final int maxDecompressedSize)Optionally one can also provide a maxDecompressRatio fifth parameter, and a decompressRatioMinSize sixth parameter to allow small inflated files with a high compression ratio to still be accepted.
Here are the additional constructor:
public CompressionFilter(final boolean compressInbound, final boolean compressOutbound,
final int compressionLevel, final int maxDecompressedSize,
final long maxDecompressRatio, final long decompressRatioMinSize)
Also note that a fluent API has been added to spare the users the pain to call a constructor with that many parameters:
CompressionFilter compressionFilter = new CompressionFilter()
.setCompressionLevel(Zlib.COMPRESSION_MAX)
.setMaxDecompressedSize(1_000_000)
.setMaxDecompressRatio(100).
.setDecompressRatioMinSize(100_000);
Applications using Apache MINA are advised to upgrade and configure their CompressionFilter instance.
- Record
CVE-2026-47321- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-409, CWE-789
- Updated
- 2026-11-02
EUVDEUVD-2026-83858
7.5
The CompressionFilter class uses ZLib to deflate and inflate data sent and received. When we inflate incoming data, the filter does not control the resulting size, and create a buffer no matter what.
Some compressed data may have a compression ration greater than 1 thousand, leading to an exhaustion of the application memory, as we don't control the deflated size.
The fix adds such a control by allowing the application developer to provide a fixed size limit, which when reached throws an exception. It also allows the user to provide a compression ratio that should not be exceeded, protected the application from small inflated files that inflate in gigantic files, but with a grace limit for the resulting size (1Mb) to avoid false positive (like a very small file inflating with a high ratio, but resulting with a acceptable size, like a few thousands bytes)
For application using this feature, it is highly recommended to create the CompressionFilter and to pass the maximum limit as a forth constructor parameter, maxDecompressedSize:
public CompressionFilter(final boolean compressInbound, final boolean compressOutbound, final int compressionLevel, final int maxDecompressedSize)Optionally one can also provide a maxDecompressRatio fifth parameter, and a decompressRatioMinSize sixth parameter to allow small inflated files with a high compression ratio to still be accepted.
Here are the additional constructor:
public CompressionFilter(final boolean compressInbound, final boolean compressOutbound,
final int compressionLevel, final int maxDecompressedSize,
final long maxDecompressRatio, final long decompressRatioMinSize)
Also note that a fluent API has been added to spare the users the pain to call a constructor with that many parameters:
CompressionFilter compressionFilter = new CompressionFilter()
.setCompressionLevel(Zlib.COMPRESSION_MAX)
.setMaxDecompressedSize(1_000_000)
.setMaxDecompressRatio(100).
.setDecompressRatioMinSize(100_000);
Applications using Apache MINA are advised to upgrade and configure their CompressionFilter instance.
- Record
EUVD-2026-83858- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-3c8x-fp36-75xv
7.5
The CompressionFilter class uses ZLib to deflate and inflate data sent and received. When we...
The CompressionFilter class uses ZLib to deflate and inflate data sent and received. When we inflate incoming data, the filter does not control the resulting size, and create a buffer no matter what.
Some compressed data may have a compression ration greater than 1 thousand, leading to an exhaustion of the application memory, as we don't control the deflated size.
The fix adds such a control by allowing the application developer to provide a fixed size limit, which when reached throws an exception. It also allows the user to provide a compression ratio that should not be exceeded, protected the application from small inflated files that inflate in gigantic files, but with a grace limit for the resulting size (1Mb) to avoid false positive (like a very small file inflating with a high ratio, but resulting with a acceptable size, like a few thousands bytes)
For application using this feature, it is highly recommended to create the CompressionFilter and to pass the maximum limit as a forth constructor parameter, maxDecompressedSize:
public CompressionFilter(final boolean compressInbound, final boolean compressOutbound, final int compressionLevel, final int maxDecompressedSize)Optionally one can also provide a maxDecompressRatio fifth parameter, and a decompressRatioMinSize sixth parameter to allow small inflated files with a high compression ratio to still be accepted.
Here are the additional constructor:
public CompressionFilter(final boolean compressInbound, final boolean compressOutbound,
final int compressionLevel, final int maxDecompressedSize,
final long maxDecompressRatio, final long decompressRatioMinSize)
Also note that a fluent API has been added to spare the users the pain to call a constructor with that many parameters:
CompressionFilter compressionFilter = new CompressionFilter()
.setCompressionLevel(Zlib.COMPRESSION_MAX)
.setMaxDecompressedSize(1_000_000)
.setMaxDecompressRatio(100).
.setDecompressRatioMinSize(100_000);
Applications using Apache MINA are advised to upgrade and configure their CompressionFilter instance.
- Record
GHSA-3c8x-fp36-75xv- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-409
- Updated
- 2026-11-02
NVD
7.5
The CompressionFilter class uses ZLib to deflate and inflate data sent and received. When we inflate incoming data, the filter does not control the resulting size, and create a buffer no matter what.
Some compressed data may have a compression ration greater than 1 thousand, leading to an exhaustion of the application memory, as we don't control the deflated size.
The fix adds such a control by allowing the application developer to provide a fixed size limit, which when reached throws an exception. It also allows the user to provide a compression ratio that should not be exceeded, protected the application from small inflated files that inflate in gigantic files, but with a grace limit for the resulting size (1Mb) to avoid false positive (like a very small file inflating with a high ratio, but resulting with a acceptable size, like a few thousands bytes)
For application using this feature, it is highly recommended to create the CompressionFilter and to pass the maximum limit as a forth constructor parameter, maxDecompressedSize:
public CompressionFilter(final boolean compressInbound, final boolean compressOutbound, final int compressionLevel, final int maxDecompressedSize)Optionally one can also provide a maxDecompressRatio fifth parameter, and a decompressRatioMinSize sixth parameter to allow small inflated files with a high compression ratio to still be accepted.
Here are the additional constructor:
public CompressionFilter(final boolean compressInbound, final boolean compressOutbound,
final int compressionLevel, final int maxDecompressedSize,
final long maxDecompressRatio, final long decompressRatioMinSize)
Also note that a fluent API has been added to spare the users the pain to call a constructor with that many parameters:
CompressionFilter compressionFilter = new CompressionFilter()
.setCompressionLevel(Zlib.COMPRESSION_MAX)
.setMaxDecompressedSize(1_000_000)
.setMaxDecompressRatio(100).
.setDecompressRatioMinSize(100_000);
Applications using Apache MINA are advised to upgrade and configure their CompressionFilter instance.
- Record
CVE-2026-47321- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-409, CWE-789
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-47321
7.5
The CompressionFilter class uses ZLib to deflate and inflate data sent and received. When we inflate incoming data, the filter does not control the resulting size, and create a buffer no matter what. Some compressed data may have a compression ration greater than 1 thousand, leading to an exhaustion of the application memory, as we don't control the deflated size. The fix adds such a control by allowing the application developer to provide a fixed size limit, which when reached throws an exception. It also allows the user to provide a compression ratio that should not be exceeded, protected the application from small inflated files that inflate in gigantic files, but with a grace limit for the resulting size (1Mb) to avoid false positive (like a very small file inflating with a high ratio, but resulting with a acceptable size, like a few thousands bytes) For application using this feature, it is highly recommended to create the CompressionFilter and to pass the maximum limit as a forth constructor parameter, maxDecompressedSize: public CompressionFilter(final boolean compressInbound, final boolean compressOutbound, final int compressionLevel, final int maxDecompressedSize)Optionally one can also provide a maxDecompressRatio fifth parameter, and a decompressRatioMinSize sixth parameter to allow small inflated files with a high compression ratio to still be accepted. Here are the additional constructor: public CompressionFilter(final boolean compressInbound, final boolean compressOutbound, final int compressionLevel, final int maxDecompressedSize, final long maxDecompressRatio, final long decompressRatioMinSize) Also note that a fluent API has been added to spare the users the pain to call a constructor with that many parameters: CompressionFilter compressionFilter = new CompressionFilter() .setCompressionLevel(Zlib.COMPRESSION_MAX) .setMaxDecompressedSize(1_000_000) .setMaxDecompressRatio(100). .setDecompressRatioMinSize(100_000); Applications using Apache MINA are advised to upgrade and configure their CompressionFilter instance.
- Record
DEBIAN-CVE-2026-47321- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVRHLW-2026-2cb9a31c02a7f38b
7.5
Lightwell Security Advisory: mina-filter-compression 2.2.5.rhlw-00008
Red Hat Lightwell has released org.apache.mina:mina-filter-compression 2.2.5.rhlw-00008 with a backported security fix.
CVE-2026-47321: The CompressionFilter class uses ZLib to deflate and inflate data sent and received. When we inflate incoming data, the filter does not control the resulting size, and create a buffer no matter what.
Some compressed data may have a compression ration greater than 1 thousand, leading to an exhaustion of the application memory, as we don't control the deflated size.
The fix adds such a control by allowing the application developer to provide a fixed size limit, which when reached throws an exception. It also allows the user to provide a compression ratio that should not be exceeded, protected the application from small inflated files that inflate in gigantic files, but with a grace limit for the resulting size (1Mb) to avoid false positive (like a very small file inflating with a high ratio, but resulting with a acceptable size, like a few thousands bytes)
For application using this feature, it is highly recommended to create the CompressionFilter and to pass the maximum limit as a forth constructor parameter, maxDecompressedSize:
public CompressionFilter(final boolean compressInbound, final boolean compressOutbound, final int compressionLevel, final int maxDecompressedSize)Optionally one can also provide a maxDecompressRatio fifth parameter, and a decompressRatioMinSize sixth parameter to allow small inflated files with a high compression ratio to still be accepted.
Here are the additional constructor:
public CompressionFilter(final boolean compressInbound, final boolean compressOutbound,
final int compressionLevel, final int maxDecompressedSize,
final long maxDecompressRatio, final long decompressRatioMinSize)
Also note that a fluent API has been added to spare the users the pain to call a constructor with that many parameters:
CompressionFilter compressionFilter = new CompressionFilter()
.setCompressionLevel(Zlib.COMPRESSION_MAX)
.setMaxDecompressedSize(1_000_000)
.setMaxDecompressRatio(100).
.setDecompressRatioMinSize(100_000);
Applications using Apache MINA are advised to upgrade and configure their CompressionFilter instance.
This patched artifact is a drop-in replacement for org.apache.mina:mina-filter-compression 2.2.5 from Maven Central.
- Record
RHLW-2026-2cb9a31c02a7f38b- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-47321
7.5
The CompressionFilter class uses ZLib to deflate and inflate data sent and received. When we inflate incoming data, the filter does not control the resulting size, and create a buffer no matter what. Some compressed data may have a compression ration greater than 1 thousand, leading to an exhaustion of the application memory, as we don't control the deflated size. The fix adds such a control by allowing the application developer to provide a fixed size limit, which when reached throws an exception. It also allows the user to provide a compression ratio that should not be exceeded, protected the application from small inflated files that inflate in gigantic files, but with a grace limit for the resulting size (1Mb) to avoid false positive (like a very small file inflating with a high ratio, but resulting with a acceptable size, like a few thousands bytes) For application using this feature, it is highly recommended to create the CompressionFilter and to pass the maximum limit as a forth constructor parameter, maxDecompressedSize: public CompressionFilter(final boolean compressInbound, final boolean compressOutbound, final int compressionLevel, final int maxDecompressedSize)Optionally one can also provide a maxDecompressRatio fifth parameter, and a decompressRatioMinSize sixth parameter to allow small inflated files with a high compression ratio to still be accepted. Here are the additional constructor: public CompressionFilter(final boolean compressInbound, final boolean compressOutbound, final int compressionLevel, final int maxDecompressedSize, final long maxDecompressRatio, final long decompressRatioMinSize) Also note that a fluent API has been added to spare the users the pain to call a constructor with that many parameters: CompressionFilter compressionFilter = new CompressionFilter() .setCompressionLevel(Zlib.COMPRESSION_MAX) .setMaxDecompressedSize(1_000_000) .setMaxDecompressRatio(100). .setDecompressRatioMinSize(100_000); Applications using Apache MINA are advised to upgrade and configure their CompressionFilter instance.
- Record
UBUNTU-CVE-2026-47321- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
minaDebian:12 |
All versions, plus listed versions 1.1.7.dfsg-131.1.7.dfsg-14 |
None known |
mina2Debian:12 |
All versions, plus listed versions 2.2.1-32.2.1-42.2.9-1 |
None known |
mina2Debian:13 |
All versions, plus listed versions 2.2.1-42.2.9-1 |
None known |
mina2Debian:14 |
before 2.2.9-1, plus listed versions 2.2.1-4 |
2.2.9-1 |
org.apache.mina:mina-filter-compressionRed Hat Lightwell:Maven |
before 2.2.5.rhlw-00008, plus listed versions 1.0.01.0.11.0.101.0.21.0.3 Show 45 moreShow less1.0.41.0.51.0.61.0.71.0.81.0.91.1.01.1.11.1.21.1.31.1.41.1.51.1.61.1.72.0.02.0.0-M12.0.0-M22.0.0-M32.0.0-M42.0.0-M52.0.0-M62.0.0-RC12.0.12.0.102.0.112.0.122.0.132.0.142.0.152.0.162.0.172.0.182.0.192.0.22.0.202.0.212.0.222.0.232.0.242.0.252.0.262.0.272.0.282.0.292.0.3 |
2.2.5.rhlw-00008 |
minaUbuntu:16.04:LTS |
All versions, plus listed versions 1.1.7.dfsg-11 |
None known |
mina2Ubuntu:16.04:LTS |
All versions, plus listed versions 2.0.7+dfsg-22.0.9-12.0.9-2 |
None known |
minaUbuntu:18.04:LTS |
All versions, plus listed versions 1.1.7.dfsg-111.1.7.dfsg-12 |
None known |
mina2Ubuntu:18.04:LTS |
All versions, plus listed versions 2.0.16-2 |
None known |
minaUbuntu:20.04:LTS |
All versions, plus listed versions 1.1.7.dfsg-13 |
None known |
Show 8 moreShow less
| Package | Affected | Fixed |
|---|---|---|
mina2Ubuntu:20.04:LTS |
All versions, plus listed versions 2.0.19-2 |
None known |
minaUbuntu:22.04:LTS |
All versions, plus listed versions 1.1.7.dfsg-13 |
None known |
mina2Ubuntu:Pro:22.04:LTS |
All versions, plus listed versions 2.1.4-22.1.5-12.1.5-1ubuntu0.1~esm1 |
None known |
minaUbuntu:24.04:LTS |
All versions, plus listed versions 1.1.7.dfsg-131.1.7.dfsg-13ubuntu1 |
None known |
mina2Ubuntu:Pro:24.04:LTS |
All versions, plus listed versions 2.2.1-32.2.1-3ubuntu0.1~esm1 |
None known |
mina2Ubuntu:25.10 |
All versions, plus listed versions 2.2.1-32.2.1-4 |
None known |
mina2Ubuntu:26.10 |
All versions, plus listed versions 2.2.1-42.2.1-4ubuntu12.2.9-1 |
None known |
mina2Ubuntu:Pro:26.04:LTS |
All versions, plus listed versions 2.2.1-42.2.1-4ubuntu0.1~esm1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-47321 is a high vulnerability (CVSS 7.5) in Apache Software Foundation Mina, published September 21, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.49%, the 42nd percentile. Fixed in mina2 2.2.9-1.
References
Left out here: 30 versions. The JSON record has them.