# CVE-2026-81881: radare2: Heap out-of-bounds read in radare2 Mach-O Swift metadata parser

> An attacker can cause a denial of service in radare2 by providing a crafted Mach-O file that triggers a heap out-of-bounds read in the Swift metadata parser.

- **Severity:** Low 3.3 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 22 Sep 2026
- **Updated:** 22 Sep 2026
- **Also known as:** GHSA-q4w7-225g-64j9, UBUNTU-CVE-2026-81881

## What is CVE-2026-81881?

CVE-2026-81881 is a low-severity memory corruption vulnerability in Radare Radare2, published on 22 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

radare2 is a UNIX-like reverse engineering framework and command-line toolset. Prior to 6.2.0, radare2's Mach-O Swift field-metadata parser was vulnerable because a relative Swift field pointer could be lower than the field-metadata section base, making subtraction produce a negative logical index. The vulnerability is triggered by parsing Swift type and class metadata from a crafted Mach-O file. The derived index was used to read four bytes immediately before the allocated field-metadata buffer. This can cause incorrect metadata processing or process termination; no attacker-observable memory disclosure has been demonstrated. This issue is fixed in version 6.2.0.

Weakness: CWE-191 (Integer Underflow (Wrap or Wraparound)), CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-81881?

It affects 1 product.


Products: Radare Radare2.

## How do I fix CVE-2026-81881?

Upgrade to a fixed version.

## Is CVE-2026-81881 being exploited?

There is no known exploitation of CVE-2026-81881 in the wild and no public exploit code.

## Other vulnerabilities in Radare Radare2

- [CVE-2025-1864](https://insights.sbomify.com/CVE-2025-1864/): Buffer Overflow and Potential Code Execution in Radare2 (critical 10.0)
- [CVE-2025-1744](https://insights.sbomify.com/CVE-2025-1744/): Out-of-bounds Write in radare2 (critical 10.0)
- [CVE-2021-32494](https://insights.sbomify.com/CVE-2021-32494/): Denial of service in radare2 (critical 10.0)
- [CVE-2021-32495](https://insights.sbomify.com/CVE-2021-32495/): Use after free in radare2 (critical 10.0)
- [CVE-2024-29646](https://insights.sbomify.com/CVE-2024-29646/): Memory corruption in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-81881 and fix it if it is affected.

What it is: CVE-2026-81881 is a low-severity memory corruption vulnerability in Radare Radare2, published on 22 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-81881 in the wild and no public exploit code.

Affected product: Radare Radare2. 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-2026-81881/ (Markdown: https://insights.sbomify.com/CVE-2026-81881/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-81881
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-81881
- OSV: https://osv.dev/vulnerability/CVE-2026-81881

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-81881/
Summaries are generated and may contain mistakes; the official description above is the record.