CVE-2026-13503Public exploitNetwork attack vector

File disclosure via tokenVocab path traversal

Published Jun 28, 2026 · Updated Jun 28, 2026

Path traversal in ANTLR 4 4.13.0 through 4.13.2 allows remote attackers to read files via a crafted tokenVocab grammar option. TokenVocabParser.getImportedVocabFile appends the option value and .tokens extension to library, output, or grammar paths without rejecting traversal sequences, and load opens the resulting file. Exposure requires an application or build service to process attacker-controlled grammars; access is limited to files readable by that process whose names end in .tokens.

CVSS severity5.3
Medium
EPSS probability0.77%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Path traversal in ANTLR 4 4.13.0 through 4.13.2 allows remote attackers to read files via a crafted tokenVocab grammar option. TokenVocabParser.getImportedVocabFile appends the option value and .tokens extension to library, output, or grammar paths without rejecting traversal sequences, and load opens the resulting file. Exposure requires an application or build service to process attacker-controlled grammars; access is limited to files readable by that process whose names end in .tokens.

The record

CVE
CVE-2026-13503
Published
Jun 28, 2026
Updated
Jun 28, 2026
Vendor
ANTLR
Product
ANTLR 4
Classifications
CWE-22, T1005
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 28, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 28, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.13.0
  2. Affected versionversion=4.13.1
  3. Affected versionversion=4.13.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ANTLR · ANTLR 4version=4.13.0; version=4.13.1; version=4.13.2

Published CVSS scores

5.3VulDB CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-22Path Traversal
T1005Data from Local System

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo