# CVE-2025-7844: Memory corruption in wolfTPM

> Attacker can trigger stack buffer overflow in wolfTPM by exporting large RSA keys if MAX_RSA_KEY_BITS is misconfigured, risking code execution.

- **Severity:** Low 1.0 (`CVSS:4.0/AV:P/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L/U:Green`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 4 Aug 2025
- **Updated:** 5 Aug 2025
- **Also known as:** GHSA-c7fc-3c5j-j956

## What is CVE-2025-7844?

CVE-2025-7844 is a low-severity memory corruption vulnerability in wolfSSL Inc. wolfTPM, published on 4 Aug 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Exporting a TPM based RSA key larger than 2048 bits from the TPM could overrun a stack buffer if the default `MAX_RSA_KEY_BITS=2048` is used. If your TPM 2.0 module supports RSA key sizes larger than 2048 bit and your applications supports creating or importing an RSA private or public key larger than 2048 bits and your application calls `wolfTPM2_RsaKey_TpmToWolf` on that key, then a stack buffer could be overrun. If the `MAX_RSA_KEY_BITS` build-time macro is set correctly (RSA bits match what TPM hardware is capable of) for the hardware target, then a stack overrun is not possible.

Weakness: CWE-121 (Stack-based Buffer Overflow)

## Which versions are affected by CVE-2025-7844?


## How do I fix CVE-2025-7844?

No fix has been published for CVE-2025-7844 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-7844 being exploited?

There is no known exploitation of CVE-2025-7844 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-7844 and fix it if it is affected.

What it is: CVE-2025-7844 is a low-severity memory corruption vulnerability in wolfSSL Inc. wolfTPM, published on 4 Aug 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-7844 in the wild and no public exploit code.

Affected product: wolfSSL Inc. wolfTPM. 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-2025-7844/ (Markdown: https://insights.sbomify.com/CVE-2025-7844/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-7844
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-7844
- OSV: https://osv.dev/vulnerability/CVE-2025-7844

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-7844/
Summaries are generated and may contain mistakes; the official description above is the record.