CVE-2024-56337: Apache Tomcat · Time-of-check Time-of-use (TOCTOU) Race Condition
Affects Apache TomcatSource CVE Database V5
Mentioned vulnerabilities
Not known to be exploited · CVSS 9.8 Critical.
Data as of 26 Oct 2026, 12:29 UTC
- EPSS
- 8.9% chance of exploitation in 30 days – higher than 95% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 20 Dec 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Mavenorg.apache.tomcat/tomcatpkg:maven/org.apache.tomcat/tomcatOther threats | Affected
| Fixed in– |
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 immediately assess their Apache Tomcat deployments to identify affected versions (8.5.0 through 11.0.1 and certain EOL versions). They should upgrade to Tomcat 11.0.3, 10.1.35, or 9.0.99 or later, which include built-in mitigations. If upgrading is not immediately feasible, organizations must ensure the default servlet write feature is disabled (readonly initialization parameter set to true) on case-insensitive file systems. Additionally, for systems running Java 8 or Java 11, explicitly set the system property sun.io.useCanonCaches to false to prevent stale canonical path caching. For Java 17, verify that sun.io.useCanonCaches is either unset or set to false. For Java 21 and newer, no action is required regarding this property. Organizations should also audit their file system types and avoid enabling write access on case-insensitive file systems unless necessary. Implementing strict access controls and monitoring for unusual file system activity related to Tomcat deployments can help detect exploitation attempts. Finally, organizations should stay informed of any emerging exploits and apply security patches promptly.
Description
Time-of-check Time-of-use (TOCTOU) Race Condition vulnerability in Apache Tomcat. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.1, from 10.1.0-M1 through 10.1.33, from 9.0.0.M1 through 9.0.97. The following versions were EOL at the time the CVE was created but are known to be affected: 8.5.0 though 8.5.100. Other, older, EOL versions may also be affected. The mitigation for CVE-2024-50379 was incomplete. Users running Tomcat on a case insensitive file system with the default servlet write enabled (readonly initialisation parameter set to the non-default value of false) may need additional configuration to fully mitigate CVE-2024-50379 depending on which version of Java they are using with Tomcat: - running on Java 8 or Java 11: the system property sun.io.useCanonCaches must be explicitly set to false (it defaults to true) - running on Java 17: the system property sun.io.useCanonCaches, if set, must be set to false (it defaults to false) - running on Java 21 onwards: no further configuration is required (the system property and the problematic cache have been removed) Tomcat 11.0.3, 10.1.35 and 9.0.99 onwards will include checks that sun.io.useCanonCaches is set appropriately before allowing the default servlet to be write enabled on a case insensitive file system. Tomcat will also set sun.io.useCanonCaches to false by default where it can.