Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
Apache Tomcat versions 8.5.7 through 8.5.63 and 9.0.0-M11 through 9.0.43 are affected, along with the tomcat-coyote, tomcat-embed-core and tomcat-embed-programmatic packages in those ranges. The source gives few details on the attack conditions, but it describes an error message that can expose sensitive information. Upgrade to Tomcat 8.5.64 or 9.0.44 or later.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 5.3 | Medium | 3.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N | GitHub Advisory Database |
- CISA KEV Not listed.
- EPSS 0.14, the 96th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 14:20 UTC First seen by agentprime
- 31 Oct 2026, 14:20 UTC Confirmed by OSV
Sources
- GitHub Advisory Database: GHSA-f4qf-m5gf-8jm8
- OSV: GHSA-f4qf-m5gf-8jm8
- nvd.nist.gov/vuln/detail/CVE-2024-21733
- github.com/apache/tomcat/commit/86ccc43940861703c2be96a5f35384407522125a
- github.com/apache/tomcat/commit/ce4b154e7b48f66bd98858626347747cd2514311
- github.com/apache/tomcat
- lists.apache.org/thread/h9bjqdd0odj6lhs2o96qgowcc6hb0cfz
- lists.debian.org/debian-lts-announce/2025/01/msg00009.html
- security.netapp.com/advisory/ntap-20240216-0005
- tomcat.apache.org/security-8.html
- tomcat.apache.org/security-9.html
- packetstormsecurity.com/files/176951/Apache-Tomcat-8.5.63-9.0.43-HTTP-Response-Smuggling.html
- www.openwall.com/lists/oss-security/2024/01/19/2