CVE-2026-111816
Apache Traffic Server: A malformed 302 response bypasses parse-error rejection through the Transfer-Encoding: chunked carve-out
Description
Apache Traffic Server forwarded a malformed 302 response that should have been rejected as a parse error, because the Transfer-Encoding: chunked carve-out bypassed the rejection path. A response that two peers can read differently is then stored and served, allowing cache poisoning and response-framing desync. 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.
INFO
Published Date :
Oct. 21, 2026, 7:16 p.m.
Last Modified :
Oct. 26, 2026, 10:10 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | CRITICAL | f0158376-9dc2-43b6-827c-5f631a4d8d09 | ||||
| CVSS 3.1 | CRITICAL | MITRE-CVE | ||||
| CVSS 3.1 | CRITICAL | [email protected] | ||||
| CVSS 4.0 | CRITICAL | f0158376-9dc2-43b6-827c-5f631a4d8d09 | ||||
| CVSS 4.0 | CRITICAL | [email protected] |
Solution
- Upgrade Apache Traffic Server to version 9.2.16.
- Upgrade Apache Traffic Server to version 10.1.5.
- Upgrade Apache Traffic Server to version 10.2.1.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-111816.
| URL | Resource |
|---|---|
| https://lists.apache.org/thread/r95dq29ywcd1f4x30snxlqmb12z4s4kc |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-111816 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-111816
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-111816 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-111816 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Translated by [email protected]
Oct. 26, 2026
Action Type Old Value New Value Added Translation Title: Apache Traffic Server de Apache Software Foundation, Description: Apache Traffic Server reenvió una respuesta 302 malformada que debería haber sido rechazada como un error de análisis, porque la excepción de ’Transfer-Encoding: chunked’ eludió la ruta de rechazo. Una respuesta que dos pares pueden interpretar de manera diferente se almacena y se sirve, lo que permite el envenenamiento de caché y la desincronización del encuadre de respuesta. Este problema afecta a Apache Traffic Server: desde la versión 8.0.0 hasta la 8.1.11 incluida, desde la 9.0.0 hasta la 9.2.15 incluida, desde la 10.0.0 hasta la 10.1.4 incluida, y la versión 10.2.0. Se recomienda a los usuarios actualizar a las versiones 9.2.16, 10.1.5 o 10.2.1, que solucionan el problema. -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Oct. 23, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-111816', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-10-23T20:52:14.941978Z'} -
New CVE Received by [email protected]
Oct. 21, 2026
Action Type Old Value New Value Added Description Apache Traffic Server forwarded a malformed 302 response that should have been rejected as a parse error, because the Transfer-Encoding: chunked carve-out bypassed the rejection path. A response that two peers can read differently is then stored and served, allowing cache poisoning and response-framing desync. 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:L/SI:H/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 Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:N Added CWE CWE-444 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/111xxx/CVE-2026-111816.json">CVE-2026-111816</a> Added Reference https://lists.apache.org/thread/r95dq29ywcd1f4x30snxlqmb12z4s4kc