CVE-2026-13503: Antlr ANTLR4

Medium severity, CVSS 5.3. EPSS: 0.8% chance of exploitation in the next 30 days.

A vulnerability was detected in antlr ANTLR4 up to 4.13.2. Affected by this issue is the function getImportedVocabFile of the file tool/src/org/antlr/v4/parse/TokenVocabParser.java of the component tokenVocab Grammar Option Handler. The manipulation results in path traversal. The attack can be executed remotely. The exploit is now public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

Affected products

• Antlr ANTLR4: version 4.13.0 only; version 4.13.1 only; version 4.13.2 only

Published 2026-06-28. Last modified 2026-06-29.