# CVE-2026-0861: Integer overflow in memalign leads to heap corruption

> An integer overflow in glibc's memalign functions can lead to heap corruption, potentially allowing code execution if an attacker controls both size and alignment arguments.

- **Severity:** High 8.4 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **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:** 14 Jan 2026
- **Updated:** 29 Apr 2026
- **Also known as:** AZL-74547, AZL-74636, BELL-CVE-2026-0861, CLSA-2026-1770741856, CLSA-2026-1772463357, DEBIAN-CVE-2026-0861, ECHO-9177-1522-4a81, GHSA-5pf6-63v3-88hw, MINI-3jx9-w69q-v5j9, MINI-728x-87x4-qfr5, MINI-9cxr-c34r-7965, SUSE-SU-2026:0347-1, SUSE-SU-2026:0499-1, SUSE-SU-2026:0827-1, SUSE-SU-2026:20544-1, SUSE-SU-2026:20608-1, UBUNTU-CVE-2026-0861

## What is CVE-2026-0861?

CVE-2026-0861 is a high-severity vulnerability in Gnu Glibc, published on 14 Jan 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Passing too large an alignment to the memalign suite of functions (memalign, posix_memalign, aligned_alloc) in the GNU C Library version 2.30 to 2.42 may result in an integer overflow, which could consequently result in a heap corruption.

Note that the attacker must have control over both, the size as well as the alignment arguments of the memalign function to be able to exploit this.  The size parameter must be close enough to PTRDIFF_MAX so as to overflow size_t along with the large alignment argument.  This limits the malicious inputs for the alignment for memalign to the range [1<<62+ 1, 1<<63] and exactly 1<<63 for posix_memalign and aligned_alloc.

Typically the alignment argument passed to such functions is a known constrained quantity (e.g. page size, block size, struct sizes) and is not attacker controlled, because of which this may not be easily exploitable in practice.  An application bug could potentially result in the input alignment being too large, e.g. due to a different buffer overflow or integer overflow in the application or its dependent libraries, but that is again an uncommon usage pattern given typical sources of alignments.

Weakness: CWE-190 (Integer Overflow or Wraparound)

## Which versions are affected by CVE-2026-0861?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `glibc-livepatches` | SUSE:Linux Enterprise Live Patching 15 SP4 | All versions | 0.3-150400.3.11.1 |
| `glibc-livepatches` | SUSE:Linux Enterprise Live Patching 15 SP5 | All versions | 0.3-150400.3.11.1 |
| `glibc-livepatches` | SUSE:Linux Enterprise Live Patching 15 SP6 | All versions | 0.3-150600.8.2.1 |
| `glibc-livepatches` | SUSE:Linux Enterprise Live Patching 15 SP7 | All versions | 0.3-150700.10.4.1 |

Products: Gnu Glibc.

## How do I fix CVE-2026-0861?

Upgrade to a fixed version.

## Is CVE-2026-0861 being exploited?

There is no known exploitation of CVE-2026-0861 in the wild and no public exploit code.

## Other vulnerabilities in Gnu Glibc

- [CVE-2026-5450](https://insights.sbomify.com/CVE-2026-5450/): scanf %mc off-by-one heap buffer overflow (critical 9.8)
- [CVE-2023-25139](https://insights.sbomify.com/CVE-2023-25139/): Memory corruption in n/a (critical 9.8)
- [CVE-1999-0199](https://insights.sbomify.com/CVE-1999-0199/): Other in n/a (critical 9.8)
- [CVE-2019-1010022](https://insights.sbomify.com/CVE-2019-1010022/): Security feature bypass in glibc (critical 9.8)
- [CVE-2005-3590](https://insights.sbomify.com/CVE-2005-3590/): Memory corruption in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-0861 and fix it if it is affected.

What it is: CVE-2026-0861 is a high-severity vulnerability in Gnu Glibc, published on 14 Jan 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-2026-0861 in the wild and no public exploit code.

Affected product: Gnu Glibc. 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-2026-0861/ (Markdown: https://insights.sbomify.com/CVE-2026-0861/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-0861
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-0861
- OSV: https://osv.dev/vulnerability/CVE-2026-0861

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-0861/
Summaries are generated and may contain mistakes; the official description above is the record.