CVE-2025-43973 GoBGP does not verify that the input length
An attacker can cause a denial of service in GoBGP by sending malformed RTR messages that trigger an integer overflow due to missing length verification.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-43973?
CVE-2025-43973 is a medium-severity vulnerability in GoBGP, published on 21 Apr 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
An issue was discovered in GoBGP before 3.35.0. pkg/packet/rtr/rtr.go does not verify that the input length corresponds to a situation in which all bytes are available for an RTR message.
Weakness: CWE-193
Which versions are affected by CVE-2025-43973?
6 open source packages ship an affected version, including github.com/osrg/gobgp and github.com/osrg/gobgp/v3. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/osrg/gobgp Go | All versions | None |
github.com/osrg/gobgp Go | All versions | None |
github.com/osrg/gobgp Go | All versions | None |
github.com/osrg/gobgp/v3 Go | All versions | 3.35.0 |
github.com/osrg/gobgp/v3 Go | All versions | 3.35.0 |
github.com/osrg/gobgp/v3 Go | All versions | 3.35.0 |
Products include Osrg Gobgp.
How do I fix CVE-2025-43973?
Upgrade to a fixed version.
Is CVE-2025-43973 being exploited?
There is no known exploitation of CVE-2025-43973 in the wild and no public exploit code.
Other vulnerabilities in 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-2025-43973, GHSA-c5jg-wr5v-2wp2, GO-2025-3633, MINI-5cf3-xmpx-gm8q, MINI-rqpm-f8m4-6pq8, UBUNTU-CVE-2025-43973.