CVE-2026-13502

MEDIUM
Published Jun 28, 2026 Modified Jun 29, 2026 CWE-362 CWE-367

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.

CVSS v3.1 Score

4.5
MEDIUM
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L

EPSS — Exploit Prediction

0.0009
Probability of exploitation
0.01%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-362 CWE-362
CWE-367 CWE-367

References

Frequently Asked Questions

What is CVE-2026-13502? +
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. It has a CVSS v3.1 base score of 4.5 (MEDIUM).
How severe is CVE-2026-13502? +
CVE-2026-13502 has a CVSS v3.1 score of 4.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0009, placing it in the 0th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2026-13502? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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