CVE-2024-58340: langchain ai langchain

Vulnerability summary

CVE-2024-58340 is a high (CVSS 8.7) vulnerability in langchain ai langchain. EPSS estimates a 0.48% chance of exploitation in the next 30 days, higher than 40.1% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 12-01-2026
   PublishedVulnerability first disclosed.
2. 14-07-2026
   Last modifiedVulnerability information updated.

Description

LangChain versions up to and including 0.3.1 contain a regular expression denial-of-service (ReDoS) vulnerability in the MRKLOutputParser.parse() method (libs/langchain/langchain/agents/mrkl/output_parser.py). The parser applies a backtracking-prone regular expression when extracting tool actions from model output. An attacker who can supply or influence the parsed text (for example via prompt injection in downstream applications that pass LLM output directly into MRKLOutputParser.parse()) can trigger excessive CPU consumption by providing a crafted payload, causing significant parsing delays and a denial-of-service condition.

• CWE-1333Inefficient Regular Expression ComplexityThe product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.