Skip to main content
VulnerabilityPublished Updated

CVE-2024-24549: Apache Tomcat · Improper Input Validation

Affects Apache TomcatSource CVE Database V5

0

Not known to be exploited · 23% EPSS · CVSS 7.5 High : upgrade to 8.5.99 soon.

Data as of 26 Oct 2026, 11:07 UTC

CVSS 3.1 base score
7.5High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
23.0% chance of exploitation in 30 days – higher than 97% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 8.5.99
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 17 Jul 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade org.apache.tomcat/tomcat to 8.5.99.

Affected software

ProductAffectedFixed in
Mavenorg.apache.tomcat/tomcatpkg:maven/org.apache.tomcat/tomcatOther threatsAffected
  • 8.5.0 <8.5.99
Fixed in
  • 8.5.99

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

European organizations should prioritize upgrading Apache Tomcat to the fixed versions: 11.0.0-M17, 10.1.19, 9.0.86, or 8.5.99, depending on their current deployment. In addition to patching, organizations should: 1) Review and tighten HTTP/2 header size and count limits to reasonable thresholds to reduce attack surface. 2) Implement network-level protections such as rate limiting and web application firewalls (WAFs) configured to detect and block abnormal HTTP/2 header patterns. 3) Monitor server logs and network traffic for unusual spikes in HTTP/2 requests or header anomalies indicative of exploitation attempts. 4) Employ redundancy and load balancing to mitigate potential DoS impacts. 5) Conduct regular vulnerability scans and penetration tests focusing on HTTP/2 handling. 6) Ensure incident response plans include procedures for DoS scenarios involving web servers. These steps, combined with timely patching, will significantly reduce the risk posed by this vulnerability.

Description

Denial of Service due to improper input validation vulnerability for HTTP/2 requests in Apache Tomcat. When processing an HTTP/2 request, if the request exceeded any of the configured limits for headers, the associated HTTP/2 stream was not reset until after all of the headers had been processed.This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.0-M16, from 10.1.0-M1 through 10.1.18, from 9.0.0-M1 through 9.0.85, from 8.5.0 through 8.5.98. Other, older, EOL versions may also be affected. Users are recommended to upgrade to version 11.0.0-M17, 10.1.19, 9.0.86 or 8.5.99 which fix the issue.

References

Community reviews

Loading reviews…