# CVE-2026-2241: janet-lang janet os.c os_strftime out-of-bounds

> A local attacker can trigger an out-of-bounds read in the os_strftime function, potentially causing crashes or leaking memory.

- **Severity:** Medium 4.8 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 9 Feb 2026
- **Updated:** 23 Feb 2026
- **Also known as:** GHSA-p4g6-r7g4-6g8h

## What is CVE-2026-2241?

CVE-2026-2241 is a medium-severity memory corruption vulnerability in janet-lang janet, published on 9 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability was found in janet-lang janet up to 1.40.1. This affects the function os_strftime of the file src/core/os.c. Performing a manipulation results in out-of-bounds read. The attack must be initiated from a local position. The exploit has been made public and could be used. The patch is named 0f285855f0e34f9183956be5f16e045f54626bff. To fix this issue, it is recommended to deploy a patch.

Weakness: CWE-125 (Out-of-bounds Read), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2026-2241?

It affects 1 product.


Products: Janet-Lang Janet.

## How do I fix CVE-2026-2241?

No fix has been published for CVE-2026-2241 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-2241 being exploited?

There is no known exploitation of CVE-2026-2241 in the wild and no public exploit code.

## Other vulnerabilities in janet-lang janet

- [CVE-2022-30763](https://insights.sbomify.com/CVE-2022-30763/): Janet before 1.22.0 mishandles arrays. (high 7.5)
- [CVE-2026-2869](https://insights.sbomify.com/CVE-2026-2869/): janet-lang janet handleattr specials.c janetc_varset out-of-bounds (medium 4.8)
- [CVE-2026-2240](https://insights.sbomify.com/CVE-2026-2240/): janet-lang janet compile.c janetc_pop_funcdef out-of-bounds (medium 4.8)
- [CVE-2026-2242](https://insights.sbomify.com/CVE-2026-2242/): janet-lang janet specials.c janetc_if out-of-bounds (medium 4.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-2241 and fix it if it is affected.

What it is: CVE-2026-2241 is a medium-severity memory corruption vulnerability in janet-lang janet, published on 9 Feb 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-2026-2241 in the wild and no public exploit code.

Affected product: janet-lang janet. 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-2026-2241/ (Markdown: https://insights.sbomify.com/CVE-2026-2241/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-2241
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-2241
- OSV: https://osv.dev/vulnerability/CVE-2026-2241

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-2241/
Summaries are generated and may contain mistakes; the official description above is the record.