Riskcovery

CVE-2026-77762

Apache Tomcat: Stale HPACK emitter injects trailers into recycled pooled Request

State
Published
Severity
8.1 High
Published
Sep 23, 2026
Updated
Sep 30, 2026
Reserved
Aug 21, 2026

Read the record on cve.org

Description

Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') vulnerability in Apache Tomcat allows an attacker to inject trailer fields into another HTTP/2 request.

This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.25, from 10.1.0-M1 through 10.1.59, from 9.0.39 through 9.0.121.

The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.59 through 8.5.100. Other unsupported versions may also be affected.

Users are recommended to upgrade to version 11.0.26, 10.1.60, 9.0.122, which fix the issue.

Scores

CVSSScoreVectorSource
3.18.1 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HCISA-ADP

Weaknesses

  • CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Affected Products

ProductVersions
Apache TomcatApache Software Foundation
  • 11.0.0-M1 through 11.0.25Affected
  • 10.1.0-M1 through 10.1.59Affected
  • 9.0.39 through 9.0.121Affected
  • 8.5.59 through 8.5.100Affected
  • 7.0.109 and earlierNot affected

References

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