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

> A stack-based buffer overflow in LLVM's ValueSymbolTable allows local attackers to potentially execute code or cause denial of service, though the vendor disputes its security impact.

- **Severity:** Medium 4.8 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 29 Jun 2026
- **Updated:** 7 Jul 2026
- **Also known as:** DEBIAN-CVE-2026-13573, GHSA-p6v6-grg5-r9mw, UBUNTU-CVE-2026-13573

## What is CVE-2026-13573?

CVE-2026-13573 is a medium-severity memory corruption vulnerability in llvm-project, published on 29 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official 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.

Weakness: CWE-121 (Stack-based Buffer Overflow), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2026-13573?


## How do I fix CVE-2026-13573?

No fix published yet.

## Is CVE-2026-13573 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-13573 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-13573 and fix it if it is affected.

What it is: CVE-2026-13573 is a medium-severity memory corruption vulnerability in llvm-project, published on 29 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-13573 exists.

Affected product: llvm-project. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-13573/ (Markdown: https://insights.sbomify.com/CVE-2026-13573/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-13573
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-13573
- OSV: https://osv.dev/vulnerability/CVE-2026-13573

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-13573/
Summaries are generated and may contain mistakes; the official description above is the record.