CVE-2026-34219: rust-libp2p · Integer Overflow or Wraparound
Affects rust-libp2pSource CVE Database V5
Not known to be exploited · CVSS 8.2 High : upgrade to 0.49.4 soon.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 47% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 0.49.4
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 31 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade rust-libp2p and libp2p/rust-libp2p to 0.49.4.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| libp2prust-libp2p | Affected
| Fixed in
|
crates.iolibp2p/rust-libp2ppkg:cargo/libp2p/rust-libp2pOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
The primary mitigation is to upgrade all rust-libp2p deployments to version 0.49.4 or later, where the vulnerability has been fixed. For environments where immediate upgrade is not feasible, implement network-level controls to restrict peer connections to trusted entities and monitor for anomalous PRUNE control messages with unusually large backoff values. Employ runtime monitoring and alerting on process panics or crashes related to libp2p components to enable rapid incident response. Consider implementing application-layer rate limiting or filtering of control messages to reduce exposure. Additionally, conduct thorough code reviews and fuzz testing on custom libp2p protocol extensions to detect similar integer overflow issues. Maintain up-to-date dependency management and vulnerability scanning to promptly identify and remediate vulnerable versions in development and production pipelines.
Description
libp2p-rust is the official rust language Implementation of the libp2p networking stack. Prior to version 0.49.4, the Rust libp2p Gossipsub implementation contains a remotely reachable panic in backoff expiry handling. After a peer sends a crafted PRUNE control message with an attacker-controlled, near-maximum backoff value, the value is accepted and stored as an Instant near the representable upper bound. On a later heartbeat, the implementation performs unchecked Instant + Duration arithmetic (backoff_time + slack), which can overflow and panic with: overflow when adding duration to instant. This issue is reachable from any Gossipsub peer over normal TCP + Noise + mplex/yamux connectivity and requires no further authentication beyond becoming a protocol peer. This issue has been patched in version 0.49.4.