CVE-2025-31699
Apache Traffic Server: Origin connection still owed a request body is reused, enabling request smuggling
Apache Traffic Server can return an origin connection to the shared pool while the origin is still waiting on a request body the client declared but never fully sent, including when the client used Expect: 100-continue. The origin then reads a later request on that connection as leftover body data, which lets an attacker smuggle requests past ATS access controls, disrupt other users' requests, or poison the cache.
This issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.15, from 10.0.0 through 10.1.4, 10.2.0.
Users are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1, which fix the issue.
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
- Low
- Integrity
- High
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
9.1
Apache Traffic Server: Origin connection still owed a request body is reused, enabling request smuggling
Apache Traffic Server can return an origin connection to the shared pool while the origin is still waiting on a request body the client declared but never fully sent, including when the client used Expect: 100-continue. The origin then reads a later request on that connection as leftover body data, which lets an attacker smuggle requests past ATS access controls, disrupt other users' requests, or poison the cache.
This issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.15, from 10.0.0 through 10.1.4, 10.2.0.
Users are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1, which fix the issue.
- Record
CVE-2025-31699- CVSS 4.0
- 9.1 Critical
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:L/SC:H/SI:H/SA:L - CVSS 3.1
- 8.9 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:L - Weakness
- CWE-444
- Updated
- 2026-11-02
EUVDEUVD-2025-211167
9.1
Apache Traffic Server can return an origin connection to the shared pool while the origin is still waiting on a request body the client declared but never fully sent, including when the client used Expect: 100-continue. The origin then reads a later request on that connection as leftover body data, which lets an attacker smuggle requests past ATS access controls, disrupt other users' requests, or poison the cache.
This issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.15, from 10.0.0 through 10.1.4, 10.2.0.
Users are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1, which fix the issue.
- Record
EUVD-2025-211167- CVSS 4.0
- 9.1 Critical
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:L/SC:H/SI:H/SA:L - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-4h97-h3mf-j6w7
9.1
Apache Traffic Server can return an origin connection to the shared pool while the origin is...
Apache Traffic Server can return an origin connection to the shared pool while the origin is still waiting on a request body the client declared but never fully sent, including when the client used Expect: 100-continue. The origin then reads a later request on that connection as leftover body data, which lets an attacker smuggle requests past ATS access controls, disrupt other users' requests, or poison the cache.
This issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.15, from 10.0.0 through 10.1.4, 10.2.0.
Users are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1, which fix the issue.
- Record
GHSA-4h97-h3mf-j6w7- CVSS 4.0
- 9.1 Critical
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:L/SC:H/SI:H/SA:L/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
- 8.9 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:L - Weakness
- CWE-444
- Updated
- 2026-11-02
NVD
9.1
Apache Traffic Server can return an origin connection to the shared pool while the origin is still waiting on a request body the client declared but never fully sent, including when the client used Expect: 100-continue. The origin then reads a later request on that connection as leftover body data, which lets an attacker smuggle requests past ATS access controls, disrupt other users' requests, or poison the cache.
This issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.15, from 10.0.0 through 10.1.4, 10.2.0.
Users are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1, which fix the issue.
- Record
CVE-2025-31699- CVSS 4.0
- 9.1 Critical
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:L/SC:H/SI:H/SA:L/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
- 8.9 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:L - Weakness
- CWE-444
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2025-31699
9.1
Apache Traffic Server can return an origin connection to the shared pool while the origin is still waiting on a request body the client declared but never fully sent, including when the client used Expect: 100-continue. The origin then reads a later request on that connection as leftover body data, which lets an attacker smuggle requests past ATS access controls, disrupt other users' requests, or poison the cache. This issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.15, from 10.0.0 through 10.1.4, 10.2.0. Users are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1, which fix the issue.
- Record
DEBIAN-CVE-2025-31699- CVSS 4.0
- 9.1 Critical
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:L/SC:H/SI:H/SA:L/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 - Updated
- 2026-11-02
OSVUBUNTU-CVE-2025-31699
9.1
Apache Traffic Server can return an origin connection to the shared pool while the origin is still waiting on a request body the client declared but never fully sent, including when the client used Expect: 100-continue. The origin then reads a later request on that connection as leftover body data, which lets an attacker smuggle requests past ATS access controls, disrupt other users' requests, or poison the cache. This issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.15, from 10.0.0 through 10.1.4, 10.2.0. Users are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1, which fix the issue.
- Record
UBUNTU-CVE-2025-31699- CVSS 4.0
- 9.1 Critical
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:L/SC:H/SI:H/SA:L - CVSS 3.1
- 8.9 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:L - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
trafficserverDebian:12 |
All versions, plus listed versions 9.2.0+ds-29.2.0+ds-2+deb12u19.2.1+ds-19.2.2+ds-19.2.3+ds-1 Show 9 moreShow less9.2.3+ds-1+deb12u19.2.4+ds-0+deb12u19.2.4+ds-19.2.4+ds-29.2.5+ds-0+deb12u19.2.5+ds-0+deb12u29.2.5+ds-0+deb12u39.2.5+ds-0+deb12u49.2.5+ds-1 |
None known |
trafficserverUbuntu:16.04:LTS |
All versions, plus listed versions 5.3.0-2ubuntu15.3.0-2ubuntu2 |
None known |
trafficserverUbuntu:18.04:LTS |
All versions, plus listed versions 7.0.0-57.1.2+ds-27.1.2+ds-2build17.1.2+ds-3 |
None known |
trafficserverUbuntu:Pro:20.04:LTS |
All versions, plus listed versions 8.0.5+ds-18.0.5+ds-28.0.5+ds-2build18.0.5+ds-2ubuntu18.0.5+ds-38.0.5+ds-3ubuntu0.1~esm1 |
None known |
trafficserverUbuntu:Pro:22.04:LTS |
All versions, plus listed versions 8.1.1+ds-1.19.1.1+ds-2build19.1.1+ds-2ubuntu0.1~esm19.1.1+ds-2ubuntu0.19.1.1+ds-2ubuntu0.1+esm1 |
None known |
trafficserverUbuntu:24.04:LTS |
All versions, plus listed versions 9.2.1+ds-1build19.2.2+ds-19.2.3+ds-19.2.3+ds-1+deb12u19.2.3+ds-1+deb12u1build19.2.3+ds-1+deb12u1build39.2.3+ds-1+deb12u1build49.2.3+ds-1+deb12u1ubuntu0.1 |
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-2025-31699 is a critical vulnerability (CVSS 9.1) in Apache Software Foundation Traffic Server, published October 21, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.35%, the 28th percentile. No source names a fixed version.
References
lists.apache.org/thread/r95dq29ywcd1f4x30snxlqmb12z4s4kc
nvd.nist.gov/vuln/detail/CVE-2025-31699
github.com/advisories/GHSA-4h97-h3mf-j6w7
security-tracker.debian.org/tracker/CVE-2025-31699
ubuntu.com/security/CVE-2025-31699
cve.org/CVERecord?id=CVE-2025-31699
trafficserver.apache.org/security-2026-10.html