Time-of-check Time-of-use Flaw in antlr ANTLR4 Maven Plugin
CVE-2026-13502

2LOW

Key Information:

Vendor

Antlr

Status
Antlr4
Vendor
CVE Published:
28 June 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-13502?

A time-of-check time-of-use vulnerability was discovered in the antlr ANTLR4 Maven Plugin, affecting versions up to 4.13.2. This flaw is located in the ObjectInputStream.readObject function within the GrammarDependencies.java file. It allows for potential local execution exploits due to improper synchronization between condition checks and subsequent actions. Although the attack complexity is notably high, the exploit has been publicly shared, raising concerns for users who have not yet applied necessary patches. The vendor was contacted prior to this disclosure but has not issued a response.

Affected Version(s)

ANTLR4 4.13.0

ANTLR4 4.13.1

ANTLR4 4.13.2

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-13502 - Proof of Concept

References

https://vuldb.com/vuln/374498
vdb-entrytechnical-description
https://vuldb.com/vuln/374498/cti
signaturepermissions-required
https://vuldb.com/cve/CVE-2026-13502
third-party-advisory

CVSS V4

Score:
2
Severity:
LOW
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Local
Attack Complexity:
High
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

jiazhou (VulDB User)
VulDB CNA Team
.