Remote crash via unchecked PRUNE backoff arithmetic
Published Mar 20, 2026 · Updated Mar 20, 2026
Denial of service in libp2p Gossipsub before 0.49.3 allows remote attackers to crash applications via a crafted PRUNE message. The backoff update path converts the message's unchecked 64-bit backoff to Duration and adds it to Instant::now(), causing overflow and panic. The attacker must establish a Gossipsub session and reach an application that exposes the affected listener; replaying the message can repeatedly interrupt service.
Summary
What happened
Denial of service in libp2p Gossipsub before 0.49.3 allows remote attackers to crash applications via a crafted PRUNE message. The backoff update path converts the message's unchecked 64-bit backoff to Duration and adds it to Instant::now(), causing overflow and panic. The attacker must establish a Gossipsub session and reach an application that exposes the affected listener; replaying the message can repeatedly interrupt service.
The record
- CVE
- CVE-2026-33040
- Published
- Mar 20, 2026
- Updated
- Mar 20, 2026
- Vendor
- libp2p
- Product
- rust-libp2p
- Classifications
- CWE-190, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 20, 2026CVE publishedPublication date reported by the CVE source.
- Mar 20, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 0.49.3
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Crafted ControlPrune attack scenarioproof of concept · unverified
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Technologies
Your stack
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Your stack
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