CVE-2026-13502 antlr ANTLR4 Maven Plugin GrammarDependencies.java ObjectInputStream.readObject toctou
A time-of-check time-of-use race condition in the ANTLR4 Maven Plugin allows local attackers to potentially execute arbitrary code via deserialization.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-13502?
CVE-2026-13502 is a low-severity vulnerability in ANTLR4, published on 28 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A flaw has been found in antlr ANTLR4 up to 4.13.2. This affects the function ObjectInputStream.readObject of the file antlr4-maven-plugin/src/main/java/org/antlr/mojo/antlr4/GrammarDependencies.java of the component Maven Plugin. This manipulation causes time-of-check time-of-use. The attack is restricted to local execution. A high degree of complexity is needed for the attack. It is indicated that the exploitability is difficult. The exploit has been published and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
Which versions are affected by CVE-2026-13502?
How do I fix CVE-2026-13502?
No fix published yet.
Is CVE-2026-13502 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-13502 exists.
Sources
Also known as DEBIAN-CVE-2026-13502, GHSA-h73j-vjhq-j9vg, UBUNTU-CVE-2026-13502.