---
title: "CVE-2026-41293: Apache Tomcat - HTTP/2 request headers not validated"
url: https://erroneo.us/security/cve/CVE-2026-41293/
description: "CVE-2026-41293 (org.apache.tomcat.embed:tomcat-embed-core (Maven)): Improper Input Validation vulnerability in Apache Tomcat. This issue affects Apache…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-05-12
date_modified: 2026-09-17
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-41293"
kev: false
cvss: 9.8
epss: 0.0168
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-41293: Apache Tomcat - HTTP/2 request headers not validated

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 1.7% , percentile 77: FIRST’s model estimates a 1.7% chance of exploitation activity in the next 30 days, higher than 77% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes org.apache.tomcat.embed:tomcat-embed-core (Maven) >= 10.1.0-M1, < 10.1.55, fixed in 10.1.55 ; org.apache.tomcat.embed:tomcat-embed-core (Maven) >= 11.0.0-M1, < 11.0.22, fixed in 11.0.22 ; org.apache.tomcat:tomcat (Maven) >= 10.1.0-M1, < 10.1.55, fixed in 10.1.55 ; org.apache.tomcat:tomcat (Maven) >= 11.0.0-M1, < 11.0.22, fixed in 11.0.22 . Check your lockfile, including transitive dependencies.

## What it is

Improper Input Validation vulnerability in Apache Tomcat. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.21, from 10.1.0-M1 through 10.1.54, from 9.0.0.M1 through 9.0.117, from 10.0.0-M1 through 10.0.27. Older, end of support versions may also be affected. Users are recommended to upgrade to version [FIXEDVERSION], which fixes the issue.

## Affected packages

- Maven `org.apache.tomcat.embed:tomcat-embed-core` >= 10.1.0-M1, < 10.1.55 → fixed: 10.1.55
- Maven `org.apache.tomcat.embed:tomcat-embed-core` >= 11.0.0-M1, < 11.0.22 → fixed: 11.0.22
- Maven `org.apache.tomcat:tomcat` >= 10.1.0-M1, < 10.1.55 → fixed: 10.1.55
- Maven `org.apache.tomcat:tomcat` >= 11.0.0-M1, < 11.0.22 → fixed: 11.0.22
- Maven `org.apache.tomcat.embed:tomcat-embed-core` >= 8.5.0, < 9.0.118 → fixed: 9.0.118
- Maven `org.apache.tomcat:tomcat` >= 8.5.0, < 9.0.118 → fixed: 9.0.118
- Maven `org.apache.tomcat:tomcat-coyote` >= 8.5.0, < 9.0.118 → fixed: 9.0.118
- Maven `org.apache.tomcat:tomcat-coyote` >= 10.1.0-M1, < 10.1.55 → fixed: 10.1.55
- Maven `org.apache.tomcat:tomcat-coyote` >= 11.0.0-M1, < 11.0.22 → fixed: 11.0.22

## Affected products (CVE record)

- Apache Software Foundation Apache Tomcat: 11.0.0-M1 <= 11.0.21, 10.1.0-M1 <= 10.1.54, 9.0.0.M1 <= 9.0.117, 10.0.0-M1 <= 10.0.27, 8.5.0 <= 8.5.100

## Severity

- CISA-ADP CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 1.68% probability of exploitation activity in the next 30 days; percentile 77.

## Sources

- [lists.apache.org](https://lists.apache.org/thread/qwg0q16z7xkb2qrr853wdll5531mvl1r)
- [GitHub Advisory GHSA-r29c-68gh-xp6x](https://github.com/advisories/GHSA-r29c-68gh-xp6x)
- [CVE.org record CVE-2026-41293](https://www.cve.org/CVERecord?id=CVE-2026-41293)
- [NVD entry CVE-2026-41293](https://nvd.nist.gov/vuln/detail/CVE-2026-41293)
- [openwall.com](http://www.openwall.com/lists/oss-security/2026/05/12/13)
- [github.com](https://github.com/apache/tomcat/commit/19f17a257797e8d139b33ff9c88d362a273be148)
- [github.com](https://github.com/apache/tomcat/commit/1c70480466572c9192ed412ebefcd43fc63137fd)
- [github.com](https://github.com/apache/tomcat/commit/2a2476460e823789f530a22207873ea8cd6eff3b)
- [github.com](https://github.com/apache/tomcat/commit/3915fd27e6810b14ccd21e3d900bd8faef44d3df)
- [github.com](https://github.com/apache/tomcat/commit/57c2b3bfd62792631e1df24cf4237b990a0b36fa)
- [github.com](https://github.com/apache/tomcat/commit/c2925554c677da57390f940d856871e18daaacab)
- [github.com](https://github.com/apache/tomcat/commit/cf9452443bcbf3b1a4b435ef7d624364f1b65ca3)
- [github.com](https://github.com/apache/tomcat/commit/e5cef9618c3f4fd31bd6fb1e83f0f18022280dac)
- [github.com](https://github.com/apache/tomcat/commit/f72a6174ab1f0f5a053435f80448b4f6837fe6d7)
- [tomcat.apache.org](https://tomcat.apache.org/security-10.html)
- [tomcat.apache.org](https://tomcat.apache.org/security-11.html)
- [tomcat.apache.org](https://tomcat.apache.org/security-9.html)

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Source page: https://erroneo.us/security/cve/CVE-2026-41293/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt