CVE-2026-5122 osrg GoBGP BGP OPEN Message bgp.go DecodeFromBytes access control
Remote attackers can bypass access controls in GoBGP's BGP OPEN message handler by manipulating domain name length, requiring high complexity.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-5122?
CVE-2026-5122 is a medium-severity missing authorization vulnerability in osrg GoBGP, published on 30 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A security flaw has been discovered in osrg GoBGP up to 4.3.0. This affects the function DecodeFromBytes of the file pkg/packet/bgp/bgp.go of the component BGP OPEN Message Handler. Performing a manipulation of the argument domainNameLen results in improper access controls. The attack may be initiated remotely. A high degree of complexity is needed for the attack. The exploitability is reported as difficult. The patch is named 2b09db390a3d455808363c53e409afe6b1b86d2d. It is suggested to install a patch to address this issue.
Which versions are affected by CVE-2026-5122?
It affects 1 product.
Products include Osrg Gobgp.
How do I fix CVE-2026-5122?
Apply the vendor's patch.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-5122 being exploited?
There is no known exploitation of CVE-2026-5122 in the wild and no public exploit code.
Other vulnerabilities in osrg GoBGP
- CVE-2025-43971 GoBGP panics due to a zero value for softwareVersionLen
- CVE-2026-41642 GoBGP: Remote Denial of Service (Panic) via Malformed Well-known Path Attribute
- CVE-2026-41643 GoBGP: Remote Denial of Service (Panic) in UpdatePathAttrs4ByteAs via Malformed BGP UPDATE
- CVE-2026-42285 GoBGP: Panic in AdjRib.Update via malformed BGP Update message (Nil Pointer Dereference)
- CVE-2026-37461 GoBGP has an out-of-bounds read in the ParseIP6Extended function
Sources
Also known as DEBIAN-CVE-2026-5122, GHSA-vj73-h4qp-97x2, UBUNTU-CVE-2026-5122.