# CVE-2026-7531: Use-after-free in PQC hybrid key-share handling

> A malicious TLS server can trigger a use-after-free in wolfSSL's PQC hybrid key-share handling, potentially leading to code execution or crashes.

- **Severity:** Low 2.3 (`CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 25 Jun 2026
- **Updated:** 26 Jun 2026
- **Also known as:** DEBIAN-CVE-2026-7531, GHSA-w9rp-wwm2-fwmr, JLSEC-2026-757, UBUNTU-CVE-2026-7531

## What is CVE-2026-7531?

CVE-2026-7531 is a low-severity use after free vulnerability in Wolfssl Wolfssl, published on 25 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Use-after-free in PQC hybrid key-share handling. This is an incomplete-fix follow-up to CVE-2026-5460 (released in 5.9.1): a malicious TLS 1.3 server sending a truncated PQC hybrid KeyShare can still trigger the error cleanup path to operate on freed memory.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2026-7531?

It affects 1 product.


Products: Wolfssl Wolfssl.

## How do I fix CVE-2026-7531?

Apply the vendor's patch.

## Is CVE-2026-7531 being exploited?

There is no known exploitation of CVE-2026-7531 in the wild and no public exploit code.

## Other vulnerabilities in Wolfssl Wolfssl

- [CVE-2024-5991](https://insights.sbomify.com/CVE-2024-5991/): Buffer overread in domain name matching (critical 10.0)
- [CVE-2021-37155](https://insights.sbomify.com/CVE-2021-37155/): Security feature bypass in n/a (critical 9.8)
- [CVE-2020-36177](https://insights.sbomify.com/CVE-2020-36177/): Memory corruption in n/a (critical 9.8)
- [CVE-2014-2896](https://insights.sbomify.com/CVE-2014-2896/): Memory corruption in n/a (critical 9.8)
- [CVE-2014-2897](https://insights.sbomify.com/CVE-2014-2897/): Memory corruption in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-7531 and fix it if it is affected.

What it is: CVE-2026-7531 is a low-severity use after free vulnerability in Wolfssl Wolfssl, published on 25 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-7531 in the wild and no public exploit code.

Affected product: Wolfssl Wolfssl. 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-2026-7531/ (Markdown: https://insights.sbomify.com/CVE-2026-7531/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-7531
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-7531
- OSV: https://osv.dev/vulnerability/CVE-2026-7531

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-7531/
Summaries are generated and may contain mistakes; the official description above is the record.