Unthrottled logging in Apache Traffic Server allows log-flood DoS
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 · High
- 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 versions 9.2.15, 10.1.4 and 10.2.0 are affected. The proxy writes one unthrottled diagnostic log line for each internal @ header it strips (CWE-400). A remote attacker who can send requests with many such headers makes the proxy write far more log data than the request contains, causing a denial of service.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
Description from the CNA
Apache Traffic Server 9.2.15, 10.1.4 and 10.2.0 write one unthrottled diagnostic log line for every internal @ header they strip, so a request carrying many such headers makes the proxy write far more log data than the request contains. This issue affects Apache Traffic Server: 9.2.15, 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.
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 to Apache Traffic Server 9.2.16, 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-2026-78952 Use-after-free in Apache Traffic Server wasm pluginPriority MEDIUM 44
Vendor assessments
Timeline
- 2026-10-21 Threatist record created from CVE-2026-111810
- 2026-10-21 Alias added: GHSA-fx98-vw52-fjmw
- 2026-10-23 Priority changed: MEDIUM → LOW
- 2026-10-24 CISA SSVC decision points changed
- 2026-10-24 Priority changed: LOW → MEDIUM
- 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-2026-111810 · CVE Program
- CVE-2026-111810 · NVD
- FIRST EPSS
- GHSA-fx98-vw52-fjmw · GitHub Advisory Database · CC BY 4.0
- CVE-2026-111810 · 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