Apache Traffic Server stalls chunked passthrough transfers
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-400.
Summary
Apache Traffic Server 8.1.11, 9.2.5 through 9.2.15, 10.0.0 through 10.1.4, and 10.2.0 are affected. When trailer dropping (proxy.config.http.drop_chunked_trailers) is enabled, a chunked transfer passed through the proxy waits for trailer bytes it has already discarded, which is CWE-400 resource consumption. A remote, unauthenticated attacker can stall these transfers until the connection times out.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
Description from the CNA
Apache Traffic Server can stall a chunked transfer that it passes through with its trailers removed (proxy.config.http.drop_chunked_trailers) until the connection times out, because it waits for the trailer bytes it has already dropped. Trailer dropping is on by default in 10.x. In 8.1.11 and 9.2.x it is off by default, and those versions are affected only if it is enabled. This issue affects Apache Traffic Server: 8.1.11, from 9.2.5 through 9.2.15, from 10.0.0 through 10.1.4, 10.2.0. Users are recommended to upgrade to version 10.1.5 or 10.2.1, which fix the issue.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
Upgrade Apache Traffic Server 10.x to version 10.1.5 or 10.2.1, which fix the issue.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Advisory ·
Apache Traffic Server — lists.apache.org/thread/r95dq29ywcd1f4x30snxlqmb12z4s4kc
15 records Highest priority Priority MEDIUM 10 MEDIUM, 5 LOW
Other records, highest priority first
- TI-2026-78953 Argument injection in Apache Traffic Server magick pluginPriority MEDIUM 49
- TI-2026-78957 Malformed 302 responses bypass rejection in Apache Traffic ServerPriority MEDIUM 45
- TI-2026-78964 Unthrottled logging in Apache Traffic Server allows log-flood DoSPriority MEDIUM 44
Vendor assessments
Timeline
- 2026-10-21 Threatist record created from CVE-2026-111817
- 2026-10-21 Alias added: GHSA-8jj5-9h2j-2r96
- 2026-10-23 Priority changed: MEDIUM → LOW
- 2026-10-24 CISA SSVC decision points changed
- 2026-10-29 Affected versions changed · Red Hat
- 2026-10-29 CVSS score added · Red Hat
References
More Apache vulnerabilities
- TI-2025-18529 Apache Tomcat: Potential RCE and/or information disclosure and/or information corruption with partial PUT KEVCVSS 3.1CRITICAL 10.0
- TI-2024-30292 Apache OFBiz: Confused controller-view authorization logic (forced browsing) KEVCVSS 3.1CRITICAL 9.8
- TI-2024-26062 Apache OFBiz: Unauthenticated endpoint could allow execution of screen rendering code KEVCVSS 3.1CRITICAL 9.8
- TI-2024-21190 Apache OFBiz: Path traversal leading to RCE KEVCVSS 3.1CRITICAL 9.8
- TI-2024-18186 Apache HugeGraph-Server: Command execution in gremlin KEVCVSS 3.1CRITICAL 9.8
- TI-2023-25106 Deserialization of untrusted data in Apache ActiveMQ KEVCVSS 3.1CRITICAL 10.0
Sources
- CVE-2026-111817 · CVE Program
- CVE-2026-111817 · NVD
- FIRST EPSS
- GHSA-8jj5-9h2j-2r96 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-111817 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences