# CVE-2025-57632: Memory corruption in n/a

> A buffer overflow in libsmb2 allows attackers to execute arbitrary code or cause denial of service via crafted SMB2 chained PDUs.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 25 Sep 2025
- **Updated:** 14 Jan 2026
- **Also known as:** DEBIAN-CVE-2025-57632, GHSA-h8w6-x833-p4x4, UBUNTU-CVE-2025-57632

## What is CVE-2025-57632?

CVE-2025-57632 is a high-severity memory corruption vulnerability in n/a, published on 25 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

libsmb2 6.2+ is vulnerable to Buffer Overflow. When processing SMB2 chained PDUs (NextCommand), libsmb2 repeatedly calls smb2_add_iovector() to append to a fixed-size iovec array without checking the upper bound of v->niov (SMB2_MAX_VECTORS=256). An attacker can craft responses with many chained PDUs to overflow v->niov and perform heap out-of-bounds writes, causing memory corruption, crashes, and potentially arbitrary code execution. The SMB2_OPLOCK_BREAK path bypasses message ID validation.

Weakness: CWE-120 (Buffer Copy without Checking Size of Input)

## Which versions are affected by CVE-2025-57632?


## How do I fix CVE-2025-57632?

Upgrade to a fixed version.

## Is CVE-2025-57632 being exploited?

There is no known exploitation of CVE-2025-57632 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-57632 and fix it if it is affected.

What it is: CVE-2025-57632 is a high-severity memory corruption vulnerability in n/a, published on 25 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-57632 in the wild and no public exploit code.

Affected product: n/a. 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-2025-57632/ (Markdown: https://insights.sbomify.com/CVE-2025-57632/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-57632
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-57632
- OSV: https://osv.dev/vulnerability/CVE-2025-57632

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-57632/
Summaries are generated and may contain mistakes; the official description above is the record.