Vulnerability · Published Mar 20, 2026 · Assigned by GitHub_M
CVE-2026-33040libp2p-rust: Gossipsub PRUNE.backoff Duration Overflow
High 8.7
In plain English
A high-severity integer overflow in rust-libp2p from libp2p. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 49% of all known vulnerabilities).
Official description
libp2p-rust is the official rust language Implementation of the libp2p networking stack. In versions prior to 0.49.3, the Gossipsub implementation accepts attacker-controlled PRUNE backoff values and may perform unchecked time arithmetic when storing backoff state. A specially crafted PRUNE control message with an extremely large backoff (e.g. u64::MAX) can lead to Duration/Instant overflow during backoff update logic, triggering a panic in the networking state machine. This is remotely reachable over a normal libp2p connection and does not require authentication. Any application exposing a libp2p Gossipsub listener and using the affected backoff-handling path can be crashed by a network attacker that can reach the service port. The attack can be repeated by reconnecting and replaying the crafted control message. This issue has been fixed in version 0.49.3.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu:25.10 | rust-libp2p-identity | no fix listed | UBUNTU-CVE-2026-33040 |
| Ubuntu:26.04:LTS | rust-libp2p-identity | no fix listed | UBUNTU-CVE-2026-33040 |
| Ubuntu:26.10 | rust-libp2p-identity | no fix listed | UBUNTU-CVE-2026-33040 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| libp2p | rust-libp2p | < 0.49.3 |
Weakness: CWE-190 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
References
- https://github.com/libp2p/rust-libp2p/security/advisories/GHSA-gc42-3jg7-rxr2 x_refsource_CONFIRM