# CVE-2026-2681: A flaw was found in the blst cryptographic library.

> A remote attacker can cause a denial of service in applications using the blst library by triggering an out-of-bounds stack write during key generation.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 19 Feb 2026
- **Updated:** 19 Feb 2026
- **Also known as:** GHSA-6ff8-r7x3-m73p

## What is CVE-2026-2681?

CVE-2026-2681 is a medium-severity memory corruption vulnerability, published on 19 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A flaw was found in the blst cryptographic library. This out-of-bounds stack write vulnerability, specifically in the blst_sha256_bcopy assembly routine, occurs due to a missing zero-length guard. A remote attacker can exploit this by providing a zero-length salt parameter to key generation functions, such as blst_keygen_v5(), if the application exposes this functionality. Successful exploitation leads to memory corruption and immediate process termination, resulting in a denial-of-service (DoS) condition.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2026-2681?


## How do I fix CVE-2026-2681?

No fix has been published for CVE-2026-2681 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-2681 being exploited?

There is no known exploitation of CVE-2026-2681 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-2681 and fix it if it is affected.

What it is: CVE-2026-2681 is a medium-severity memory corruption vulnerability, published on 19 Feb 2026. 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-2026-2681 in the wild and no public exploit code.

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-2026-2681/ (Markdown: https://insights.sbomify.com/CVE-2026-2681/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-2681
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-2681
- OSV: https://osv.dev/vulnerability/CVE-2026-2681

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-2681/
Summaries are generated and may contain mistakes; the official description above is the record.