SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAwaiting Analysis

CVE-2026-111816

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.

CRITICAL 9.2EPSS 0.31%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.31%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 4.0
9.2 CRITICALCVSS:4.0/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/M
EPSS
0.31% probability · 23th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-444
Source
security@apache.org
EPSS trend
0%3%5%22 October 2026: 0.24%26 October 2026: 0.31%22 October 202626 October 2026

EPSS moved from 0.2% on 22 October 2026 to 0.3% on 26 October 2026.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.