Cyber Resilience

CVE-2026-33040

Memory Safety in Protocol Libp2P-Gossipsub ≤ 0.49.3

Published
20 March 2026
Modified
01 May 2026
Patch / advisory
CVSS Score v4 8.7
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0057 44th percentile
Risk Priority 45 floored blend · peak EPSS

Summary

CVE-2026-33040 is a high-severity Integer Overflow or Wraparound (CWE-190) vulnerability in Protocol Libp2P-Gossipsub. Its CVSS base score is 8.7 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 44th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-33040 is a vulnerability in the Gossipsub implementation of libp2p-rust, the official Rust language implementation of the libp2p networking stack. In versions prior to 0.49.3, the code accepts attacker-controlled PRUNE backoff values and performs unchecked time arithmetic when storing backoff state. A specially crafted PRUNE control message with an extremely large backoff, such as u64::MAX, can cause a Duration/Instant overflow during backoff update logic, triggering a panic in the networking state machine. The vulnerability is rated with a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) and is associated with CWE-190 (Integer Overflow or Wraparound).

The vulnerability is remotely exploitable over a normal libp2p connection and does not require authentication. A network attacker who can reach the service port of any application exposing a libp2p Gossipsub listener and using the affected backoff-handling path can crash the application by sending the crafted PRUNE message. The attack is repeatable, as the attacker can reconnect and replay the message to sustain denial of service.

The issue has been addressed in libp2p-rust version 0.49.3. Additional details on the vulnerability and patch are available in the GitHub security advisory at https://github.com/libp2p/rust-libp2p/security/advisories/GHSA-gc42-3jg7-rxr2.

EU & UK References

Vulnerability Data

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…

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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.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-34219Same product: Protocol Libp2P-Gossipsub
CVE-2026-31814Same vendor: Protocol
CVE-2023-22460Same vendor: Protocol
CVE-2024-49994Shared CWE-190
CVE-2026-37540Shared CWE-190
CVE-2026-24210Shared CWE-190
CVE-2026-53482Shared CWE-190
CVE-2024-26817Shared CWE-190
CVE-2025-22081Shared CWE-190
CVE-2026-35092Shared CWE-190

Affected Assets

protocol
libp2p-gossipsub
≤ 0.49.3

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V5.2.6

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation (static analysis, fuzzing, unit tests) directly finds integer overflow defects before deployment.

Secure engineering principles require use of safe arithmetic constructs or language features that structurally eliminate integer overflow during calculation.

Input validation enforces bounds on values before arithmetic, stopping the conditions that trigger overflow or wraparound.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require use of safe arithmetic, bounds checks, and testing that prevent integer overflows.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing in development can detect integer overflows before release.

prevents

Secure SDLC mandates input validation and arithmetic checks that prevent integer overflows.

degrades

Application security requirements include bounds checking and safe arithmetic to avoid overflow conditions.

degrades

Secure architecture principles require defensive coding patterns that mitigate integer wraparound risks.

prevents

Secure coding standards explicitly forbid unsafe integer operations and mandate overflow-safe constructs.

References