# CVE-2026-92157: F Prime FileDownlink SendPartial integer overflow denial of service

Source: https://junglewise.ai/threats/cve-2026-92157-f-f-prime-is-a-framework-that-enables-development-and-deployment  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-14. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-92157 · Severity: medium · CVSS 6.5 · Published 2026-10-14

F Prime is a framework used to develop and deploy embedded software for spaceflight and other critical applications. A flaw in the FileDownlink component allows an attacker to send a specially crafted command that causes the application to crash or reset, preventing normal operation of the spacecraft or system until it is manually recovered.

Technologies: [Nasa F Prime](https://junglewise.ai/threats/technologies/f-prime). Vendors: [Nasa](https://junglewise.ai/threats/vendors/nasa).

## Quick answers

**Is CVE-2026-92157 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-92157 being exploited in the wild.

**How severe is CVE-2026-92157?** Medium severity, with a CVSS score of 6.5, published 14 October 2026.

**Which products and versions are affected?** Nasa F Prime before 4.3.0.

**Is there a fix for CVE-2026-92157?** Yes: fixed in 4.3.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-92157 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-92157?** Check whether you run Nasa F Prime at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 4.3.0

## Technical details

The SendPartial command in Svc::FileDownlink performs insufficient validation of the startOffset and length parameters; when their sum overflows a 32-bit unsigned integer, the range check is bypassed and an inconsistent m_endOffset is stored. On the first data-packet transition, the vulnerable code triggers an FW_ASSERT that aborts or resets the process, causing denial of service. The vulnerability is a classic integer overflow leading to assertion failure in externally-reachable code paths.

## Affected products

- NASA F Prime before 4.3.0

## Timeline

- 2026-10-14: disclosed
- 2026-08-12: patched: Fix commit authored; release of 4.3.0 date not specified

## References

- [https://github.com/nasa/fprime/commit/33fe2a4fe3fd5ff1b14985669fbad09f070e9914](https://github.com/nasa/fprime/commit/33fe2a4fe3fd5ff1b14985669fbad09f070e9914)
- [https://github.com/nasa/fprime/commit/95eeb5cfb44e5609eff0887f0e11e640cdacef6b](https://github.com/nasa/fprime/commit/95eeb5cfb44e5609eff0887f0e11e640cdacef6b)

## Related threats

- [NASA F Prime FileDownlink integer overflow bypass](https://junglewise.ai/threats/cve-2026-92160-f-f-prime-is-a-framework-that-enables-development-and-deployment)
- [F Prime TlmPacketizer buffer overflow in telemetry handler](https://junglewise.ai/threats/cve-2026-92159-f-f-prime-is-a-framework-that-enables-development-and-deployment)
- [F Prime integer wraparound in FpySequencer STORE bounds check](https://junglewise.ai/threats/cve-2026-92158-f-f-prime-is-a-framework-that-enables-development-and-deployment)
- [F Prime EventManager denial of service via oversized log packet](https://junglewise.ai/threats/cve-2026-92156-f-f-prime-is-a-framework-that-enables-development-and-deployment)
- [F Prime FilePacket deserialization denial of service](https://junglewise.ai/threats/cve-2026-92155-f-f-prime-is-a-framework-that-enables-development-and-deployment)