CVE-2026-13500
antlr ANTLR4 Grammar Action Block OutputFile.java code injection
Vexday Risk Score
30Low
SSVC decision (CISA)
Attend
PoC available → attend closely
CVSS 6.9EPSS —KEV nãoPoC públicaNuclei —Metasploit —Patch —
Lifecycle
28 Jun 2026Published on NVD
Recommendation: Plan a near-term fix — a public PoC already exists.
A weakness has been identified in antlr ANTLR4 up to 4.13.2. Affected is an unknown function of the file tool/src/org/antlr/v4/codegen/model/OutputFile.java of the component Grammar Action Block Handler. Executing a manipulation can lead to code injection. The attack may be launched remotely. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
Affected products
antlr · ANTLR4public PoCs found — 1
cve_referencegithub.com/wooyun123/wooyun/issues/4unverified⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
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