CyberSecBulletin
CVE-2026-65183NVD status: Analyzed

Apache Tomcat: Time-of-check Time-of-use (TOCTOU) Race Condition

Published Updated By the CyberSecBulletin desk

CVE-2026-65183 is a high-severity time-of-check time-of-use (TOCTOU) race condition vulnerability in Apache Tomcat from Apache, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Apache Tomcat versions: 11.0.0-M1 through 11.0.24; 10.1.0-M1 through 10.1.57; 9.0.42 through 9.0.120. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.4% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Tomcat to 9.0.121 or 10.1.58 or 11.0.25, whichever matches your release line, or a later version.
  2. Read the advisory on lists.apache.org for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
ApacheApache Tomcat11.0.0-M1 through 11.0.24; 10.1.0-M1 through 10.1.57; 9.0.42 through 9.0.120Not stated
ApacheTomcat9.0.42 up to, but not including, 9.0.121; 10.1.0 up to, but not including, 10.1.58; 11.0.0 up to, but not including, 11.0.259.0.121, 10.1.58, 11.0.25

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
HighSuccess depends on conditions outside the attacker's control.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CISA (ADP).

Official description

Time-of-check Time-of-use (TOCTOU) Race Condition vulnerability in Apache Tomcat when creating unix domain sockets allows an unauthorised local user to access the unix domain socket. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.24, from 10.1.0-M1 through 10.1.57, from 9.0.42 through 9.0.120. Users are recommended to upgrade to version 11.0.25, 10.1.58, 9.0.121, which fixes the issue.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Time-of-check Time-of-use (TOCTOU) Race Condition

The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.

How developers prevent this class of flaw

  • The most basic advice for TOCTOU vulnerabilities is to not perform a check before the use. This does not resolve the underlying issue of the execution of a function on a resource whose state and identity cannot be assured, but it does help to limit the false sense of security given by the check.
  • When the file being altered is owned by the current user and group, set the effective gid and uid to that of the current user and group when executing this statement.
  • Limit the interleaving of operations on files from multiple processes.

More Time-of-check Time-of-use (TOCTOU) Race Condition vulnerabilities (CWE-367)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Other vulnerabilities in Apache Tomcat

All Apache Tomcat vulnerabilities

Recent Time-of-check Time-of-use (TOCTOU) Race Condition vulnerabilities

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