Is CVE-2026-13503 in the CISA KEV catalog?

No. CVE-2026-13503 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-13503?

CVE-2026-13503 has a CVSS v3 base score of 5.3 (MEDIUM).

What is the EPSS score for CVE-2026-13503?

CVE-2026-13503 has an EPSS score of 0.55% (42th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix or mitigate CVE-2026-13503?

No published fix for CVE-2026-13503 has been found yet. Check the linked vendor advisories for guidance as it becomes available.

CVE & CISA-KEV Catalog

CVE-2026-13503

MEDIUM

5.3

CVSS v3

NVD

Description

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.

CWE-22Path Traversal

How to fix

No published remediation has been found for this vulnerability's affected products yet.

Mitigation guidance may be in the linked vendor advisories in the References section below.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityLow

IntegrityNone

AvailabilityNone

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

Exploit Intelligence

0.55%probability of exploitation in 30 days

42ndpercentile

Moderate risk: more likely to be exploited than 42% of all known CVEs.

References

Other references5

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-06-29.