# CVE-2026-53910: Heap-based Buffer Overflow in GNU diffutils

> Integer overflows in GNU diffutils diff3 allow attackers controlling diff output to trigger heap overflows, causing crashes or potential code execution.

- **Severity:** Low 2.1 (`CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:L/SI:L/SA: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:** 22 Jul 2026
- **Updated:** 27 Jul 2026
- **Also known as:** BELL-CVE-2026-53910, DEBIAN-CVE-2026-53910, ECHO-6cb2-c3d1-6736, GHSA-9pwr-gcwm-8wj5, MGASA-2026-0434, OESA-2026-3341, OESA-2026-3342, OESA-2026-3343, OESA-2026-3344, OESA-2026-3444, RHSA-2026:45327, UBUNTU-CVE-2026-53910, USN-8692-1

## What is CVE-2026-53910?

CVE-2026-53910 is a low-severity vulnerability in GNU diffutils, published on 22 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

diff3 tool from GNU diffutils is vulnerable to a heap‑based buffer overflow due to multiple signed integer overflows in line‑mapping calculations. Incorrect arithmetic in mapping line ranges can result in corrupted values being used for memory allocation and loop bounds.
When processing crafted diff output, these overflows may cause the application to allocate insufficient memory and subsequently perform out‑of‑bounds writes during internal processing. 
An attacker who can control the output of the diff program used by diff3 (e.g. via --diff-program pointing to a malicious script) can trigger out-of-bounds writes, resulting in a crash and potentially remote code execution depending on the environment.

This issue has been fixed in commit 9ff04d5b84743e331e80b589335a52c5480d1815 

NOTE:
The project maintainers claim that this is not a security issue. They state that the worst outcome this issue can cause is a crash of diff and that it cannot be used to escalate privileges.

Weakness: CWE-190 (Integer Overflow or Wraparound)

## Which versions are affected by CVE-2026-53910?


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `diffutils` | Red Hat:hummingbird:1 | All versions | 0:3.12-6.1.hum1 |

## How do I fix CVE-2026-53910?

Apply the vendor's patch.

## Is CVE-2026-53910 being exploited?

There is no known exploitation of CVE-2026-53910 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-53910 and fix it if it is affected.

What it is: CVE-2026-53910 is a low-severity vulnerability in GNU diffutils, published on 22 Jul 2026. 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-2026-53910 in the wild and no public exploit code.

Affected product: GNU diffutils. 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-2026-53910/ (Markdown: https://insights.sbomify.com/CVE-2026-53910/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53910
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53910
- OSV: https://osv.dev/vulnerability/CVE-2026-53910

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53910/
Summaries are generated and may contain mistakes; the official description above is the record.