CVE-2026-42285 GoBGP: Panic in AdjRib.Update via malformed BGP Update message (Nil Pointer Dereference)

What is CVE-2026-42285?

CVE-2026-42285 is a high-severity vulnerability in osrg gobgp, published on 7 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

GoBGP is an open source Border Gateway Protocol (BGP) implementation in the Go Programming Language. In version 4.4.0, an unauthenticated remote BGP peer can trigger a fatal panic in GoBGP by sending a specially crafted BGP UPDATE message. When the server receives a message with inconsistent attribute lengths, it improperly handles the internal state transition to a "withdraw" action, leading to a nil pointer dereference in the AdjRib.Update function. This causes the entire GoBGP process to crash, resulting in a complete loss of service availability. This issue has been patched in version 4.5.0.

Weakness: CWE-476

Which versions are affected by CVE-2026-42285?

3 open source packages ship an affected version, including github.com/osrg/gobgp/v4. It affects 1 product.

Products include Osrg Gobgp.

How do I fix CVE-2026-42285?

Upgrade github.com/osrg/gobgp/v4 to 4.5.0 or later.

Is CVE-2026-42285 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-42285 exists.

Other vulnerabilities in osrg gobgp

• CVE-2025-43971 GoBGP panics due to a zero value for softwareVersionLen High 8.6
• CVE-2026-41642 GoBGP: Remote Denial of Service (Panic) via Malformed Well-known Path Attribute High 7.5
• CVE-2026-41643 GoBGP: Remote Denial of Service (Panic) in UpdatePathAttrs4ByteAs via Malformed BGP UPDATE High 7.5
• CVE-2026-37461 GoBGP has an out-of-bounds read in the ParseIP6Extended function High 7.5
• CVE-2026-30405 GoBGP vulnerable to a denial of service via the NEXT_HOP path attribute High 7.5

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2026-42285, GHSA-p3w2-64xm-833j, GO-2026-5525.