CVE-2026-13503
Description
A flaw was found in antlr ANTLR4. A remote attacker can exploit a path traversal vulnerability by manipulating the getImportedVocabFile function within the tokenVocab Grammar Option Handler component. This could allow unauthorized access to sensitive files and directories on the system.
Statement
Successful exploitation requires a specific scenario where an application using ANTLR4 is configured to accept and parse untrusted, attacker-supplied grammar files containing a manipulated tokenVocab option.
Impact Limitations: The vulnerability is strictly limited to information disclosure via path traversal. While a remote attacker can read sensitive files that the application has permissions to access, this flaw does not inherently allow for remote code execution (RCE), data corruption, or privilege escalation on the host system.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.3 | N/A | 5.3 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | Low | N/A | Low |
| Integrity Impact | None | N/A | None |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N/E:P/RC:R
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
