# CVE-2025-48172: Integer overflow in CHMLib

> An integer overflow in CHMLib leads to a heap-based buffer overflow, potentially allowing attackers to execute arbitrary code or cause denial of service.

- **Severity:** Medium 5.6 (`CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 4 Jul 2025
- **Updated:** 8 Jul 2025
- **Also known as:** GHSA-rpc6-w47v-qqr6, UBUNTU-CVE-2025-48172, openSUSE-SU-2025:15326-1

## What is CVE-2025-48172?

CVE-2025-48172 is a medium-severity vulnerability in CHMLib, published on 4 Jul 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

CHMLib through 2bef8d0, as used in SumatraPDF and other products, has a chm_lib.c _chm_decompress_block integer overflow. There is a resultant heap-based buffer overflow in _chm_fetch_bytes.

Weakness: CWE-190 (Integer Overflow or Wraparound)

## Which versions are affected by CVE-2025-48172?


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `chmlib` | openSUSE:Tumbleweed | All versions | 0.40-26.1 |

## How do I fix CVE-2025-48172?

Apply the vendor's patch.

## Is CVE-2025-48172 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-48172 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-48172 and fix it if it is affected.

What it is: CVE-2025-48172 is a medium-severity vulnerability in CHMLib, published on 4 Jul 2025. 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-2025-48172 exists.

Affected product: CHMLib. 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-2025-48172/ (Markdown: https://insights.sbomify.com/CVE-2025-48172/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-48172
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-48172
- OSV: https://osv.dev/vulnerability/CVE-2025-48172

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-48172/
Summaries are generated and may contain mistakes; the official description above is the record.