# CVE-2026-2645: Acceptance of CertificateVerify Message before ClientKeyExchange in TLS 1.2


- **Severity:** Medium 5.5 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 19 Mar 2026
- **Updated:** 19 Mar 2026
- **Also known as:** DEBIAN-CVE-2026-2645, GHSA-cwc7-2fmx-fffq, JLSEC-2026-701, UBUNTU-CVE-2026-2645

## What is CVE-2026-2645?

CVE-2026-2645 is a medium-severity vulnerability in Wolfssl Wolfssl, published on 19 Mar 2026. 

### Official description

In wolfSSL 5.8.2 and earlier, a logic flaw existed in the TLS 1.2 server state machine implementation. The server could incorrectly accept the CertificateVerify message before the ClientKeyExchange message had been received. This issue affects wolfSSL before 5.8.4 (wolfSSL 5.8.2 and earlier is vulnerable, 5.8.4 is not vulnerable). In 5.8.4 wolfSSL would detect the issue later in the handshake. 5.9.0 was further hardened to catch the issue earlier in the handshake.

Weakness: CWE-358 (Improperly Implemented Security Check for Standard)

## Which versions are affected by CVE-2026-2645?

It affects 1 product.


Products: Wolfssl Wolfssl.

## How do I fix CVE-2026-2645?

Upgrade to a fixed version.

## Is CVE-2026-2645 being exploited?

There is no known exploitation of CVE-2026-2645 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-2026-2645 and fix it if it is affected.

What it is: CVE-2026-2645 is a medium-severity vulnerability in Wolfssl Wolfssl, published on 19 Mar 2026. 
Exploitation: There is no known exploitation of CVE-2026-2645 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-2026-2645/ (Markdown: https://insights.sbomify.com/CVE-2026-2645/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-2645
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-2645
- OSV: https://osv.dev/vulnerability/CVE-2026-2645

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-2645/
Summaries are generated and may contain mistakes; the official description above is the record.