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Critical 9.3Published Oct 21, 2026

CVE-2026-111809Apache Traffic Server: HEAD requests carrying Content-Length or Transfer-Encoding enable request smuggling

Updated under an hour ago ()

Does this affect you?

It affects Apache Software Foundation Apache Traffic Server. Add what you run to find out whether that includes you.

EPSS puts the chance of exploitation in the next 30 days at 0.22%, higher than 12% of scored CVEs.

Apache Traffic Server allows request smuggling via HEAD requests that carry Content-Length or Transfer-Encoding. 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
9.3 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:N
Weakness (CWE)
CWE-444
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
0.22% (percentile 12)
Assigned by
apache
NVD analysis
Awaiting Analysis
Record last updated
Oct 27, 2026
First seen by InfoSec Signals
Oct 21, 2026

Affected products

Affected products
Apache Software Foundation Apache Traffic Server
apache_software_foundation:apache_traffic_server (from the name)
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
CNA record

References

References

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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