CVE-2026-5720
miniupnpd Integer Underflow SOAPAction Header Parsing
miniupnpd contains an integer underflow vulnerability in SOAPAction header parsing that allows remote attackers to cause a denial of service or information disclosure by sending a malformed SOAPAction header with a single quote. Attackers can trigger an out-of-bounds memory read by exploiting improper length validation in ParseHttpHeaders(), where the parsed length underflows to a large unsigned value when passed to memchr(), causing the process to scan memory far beyond the allocated HTTP request buffer.
Attack profile
How easy it is to exploit
- Attack vector
- Adjacent network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
7.1
miniupnpd Integer Underflow SOAPAction Header Parsing
miniupnpd contains an integer underflow vulnerability in SOAPAction header parsing that allows remote attackers to cause a denial of service or information disclosure by sending a malformed SOAPAction header with a single quote. Attackers can trigger an out-of-bounds memory read by exploiting improper length validation in ParseHttpHeaders(), where the parsed length underflows to a large unsigned value when passed to memchr(), causing the process to scan memory far beyond the allocated HTTP request buffer.
- Record
CVE-2026-5720- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N - Weakness
- CWE-191, CWE-125
- Updated
- 2026-11-02
EUVDEUVD-2026-23565
7.1
miniupnpd contains an integer underflow vulnerability in SOAPAction header parsing that allows remote attackers to cause a denial of service or information disclosure by sending a malformed SOAPAction header with a single quote. Attackers can trigger an out-of-bounds memory read by exploiting improper length validation in ParseHttpHeaders(), where the parsed length underflows to a large unsigned value when passed to memchr(), causing the process to scan memory far beyond the allocated HTTP request buffer.
- Record
EUVD-2026-23565- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-q4xv-xmjx-4h94
7.1
miniupnpd contains an integer underflow vulnerability in SOAPAction header parsing that allows...
miniupnpd contains an integer underflow vulnerability in SOAPAction header parsing that allows remote attackers to cause a denial of service or information disclosure by sending a malformed SOAPAction header with a single quote. Attackers can trigger an out-of-bounds memory read by exploiting improper length validation in ParseHttpHeaders(), where the parsed length underflows to a large unsigned value when passed to memchr(), causing the process to scan memory far beyond the allocated HTTP request buffer.
- Record
GHSA-q4xv-xmjx-4h94- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H - Weakness
- CWE-125
- Updated
- 2026-11-02
NVD
7.1
miniupnpd contains an integer underflow vulnerability in SOAPAction header parsing that allows remote attackers to cause a denial of service or information disclosure by sending a malformed SOAPAction header with a single quote. Attackers can trigger an out-of-bounds memory read by exploiting improper length validation in ParseHttpHeaders(), where the parsed length underflows to a large unsigned value when passed to memchr(), causing the process to scan memory far beyond the allocated HTTP request buffer.
- Record
CVE-2026-5720- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H - Weakness
- CWE-125, CWE-191
- Updated
- 2026-11-02
OSVALPINE-CVE-2026-5720
9.1
miniupnpd contains an integer underflow vulnerability in SOAPAction header parsing that allows remote attackers to cause a denial of service or information disclosure by sending a malformed SOAPAction header with a single quote. Attackers can trigger an out-of-bounds memory read by exploiting improper length validation in ParseHttpHeaders(), where the parsed length underflows to a large unsigned value when passed to memchr(), causing the process to scan memory far beyond the allocated HTTP request buffer.
- Record
ALPINE-CVE-2026-5720- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H - Updated
- 2026-11-03
OSV
7.1
miniupnpd Integer Underflow SOAPAction Header Parsing
miniupnpd contains an integer underflow vulnerability in SOAPAction header parsing that allows remote attackers to cause a denial of service or information disclosure by sending a malformed SOAPAction header with a single quote. Attackers can trigger an out-of-bounds memory read by exploiting improper length validation in ParseHttpHeaders(), where the parsed length underflows to a large unsigned value when passed to memchr(), causing the process to scan memory far beyond the allocated HTTP request buffer.
- Record
CVE-2026-5720- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N - Weakness
- CWE-125, CWE-191
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-5720
9.1
miniupnpd contains an integer underflow vulnerability in SOAPAction header parsing that allows remote attackers to cause a denial of service or information disclosure by sending a malformed SOAPAction header with a single quote. Attackers can trigger an out-of-bounds memory read by exploiting improper length validation in ParseHttpHeaders(), where the parsed length underflows to a large unsigned value when passed to memchr(), causing the process to scan memory far beyond the allocated HTTP request buffer.
- Record
DEBIAN-CVE-2026-5720- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-5720
7.1
miniupnpd contains an integer underflow vulnerability in SOAPAction header parsing that allows remote attackers to cause a denial of service or information disclosure by sending a malformed SOAPAction header with a single quote. Attackers can trigger an out-of-bounds memory read by exploiting improper length validation in ParseHttpHeaders(), where the parsed length underflows to a large unsigned value when passed to memchr(), causing the process to scan memory far beyond the allocated HTTP request buffer.
- Record
UBUNTU-CVE-2026-5720- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N - CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H - Updated
- 2026-11-02
OSVUSN-8731-1 No score
miniupnpd vulnerability
It was discovered that MiniUPnPd contained an integer underflow vulnerability in SOAPAction header parsing. A remote attacker could use this issue to cause a denial of service or information disclosure by sending a malformed SOAPAction header with a single quote.
- Record
USN-8731-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
miniupnpdAlpine:v3.24 |
before 2.3.10-r0 | 2.3.10-r0 |
miniupnpdDebian:12 |
All versions, plus listed versions 2.3.1-12.3.10-12.3.3-12.3.4-12.3.7-12.3.7-22.3.9-12.3.9-2 |
None known |
miniupnpdDebian:13 |
before 2.3.9-2+deb13u1, plus listed versions 2.3.9-2 |
2.3.9-2+deb13u1 |
miniupnpdDebian:14 |
before 2.3.10-1, plus listed versions 2.3.9-2 |
2.3.10-1 |
miniupnpdUbuntu:Pro:16.04:LTS |
before 1.8.20140523-4.1+deb9u2ubuntu0.1~esm1, plus listed versions 1.8.20140523-41.8.20140523-4.1+deb9u1build0.16.04.11.8.20140523-4.1+deb9u2build0.16.04.1 |
1.8.20140523-4.1+deb9u2ubuntu0.1~esm1 |
miniupnpdUbuntu:Pro:18.04:LTS |
before 2.0.20171212-2ubuntu0.1~esm1, plus listed versions 1.8.20140523-4.11.8.20140523-4.22.0.20171212-12.0.20171212-2 |
2.0.20171212-2ubuntu0.1~esm1 |
miniupnpdUbuntu:Pro:20.04:LTS |
before 2.1-6.1ubuntu0.1~esm1, plus listed versions 2.1-6ubuntu22.1-6.1 |
2.1-6.1ubuntu0.1~esm1 |
miniupnpdUbuntu:Pro:22.04:LTS |
before 2.2.3-1ubuntu0.1~esm1, plus listed versions 2.2.1-12.2.3-1 |
2.2.3-1ubuntu0.1~esm1 |
miniupnpdUbuntu:Pro:24.04:LTS |
before 2.3.4-1ubuntu0.1~esm1, plus listed versions 2.3.3-12.3.4-1 |
2.3.4-1ubuntu0.1~esm1 |
miniupnpdUbuntu:25.10 |
All versions, plus listed versions 2.3.7-22.3.9-2 |
None known |
miniupnpdUbuntu:Pro:26.04:LTS |
before 2.3.9-2ubuntu0.1~esm1, plus listed versions 2.3.9-22.3.9-2build1 |
2.3.9-2ubuntu0.1~esm1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, aliases, references | OSV | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-5720 is a high vulnerability (CVSS 7.1) in Miniupnp Project Miniupnpd, published April 17, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.67%, the 52nd percentile. Fixed in miniupnpd 2.3.10-r0.
References
github.com/miniupnp/miniupnp
github.com/miniupnp/miniupnp/commit/f56bd09b2f2650126b832c5f30a65a09e28167fa
vulncheck.com/advisories/miniupnpd-integer-underflow-soapaction-header-parsing
nvd.nist.gov/vuln/detail/CVE-2026-5720
github.com/miniupnp/miniupnp/commit/a0ee71e9fa66b60052bb3d2cf84380b79db3f8c8
github.com/miniupnp/miniupnp/commit/b5e5d2eb069822b7f00d56c8e61033b9d500e60c
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github.com/advisories/GHSA-q4xv-xmjx-4h94
security.alpinelinux.org/vuln/CVE-2026-5720
github.com/CVEProject/cvelistV5/tree/main/cves/2026/5xxx/CVE-2026-5720.json
security-tracker.debian.org/tracker/CVE-2026-5720
ubuntu.com/security/CVE-2026-5720
cve.org/CVERecord?id=CVE-2026-5720
ubuntu.com/security/notices/USN-8731-1