Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2023-39533

CVE-2023-39533HIGH

libp2p nodes vulnerable to attack using large RSA keys

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  N  N  H    7.5   .0150   73.4     —

AFFECTED
  Product    Versions    Fixed
  go-libp2p  < 0.27.8 –  —

TIMELINE
  Aug 3   Reserved by GitHub_M
  Aug 8   Published (CNA: GitHub_M)
  Sep 1   EXPLOIT PUBLISHED — CVE-2023-39533 (libp2p go-libp2p). Public exploit reference added.

CWE-770 · CNA: GitHub_M · CVSS v3.1 · 9 references · NVD status: Modified

Description

go-libp2p is the Go implementation of the libp2p Networking Stack. Prior to versions 0.27.8, 0.28.2, and 0.29.1 malicious peer can use large RSA keys to run a resource exhaustion attack & force a node to spend time doing signature verification of the large key. This vulnerability is present in the core/crypto module of go-libp2p and can occur during the Noise handshake and the libp2p x509 extension verification step. To prevent this attack, go-libp2p versions 0.27.8, 0.28.2, and 0.29.1 restrict RSA keys to <= 8192 bits. To protect one's application, it is necessary to update to these patch releases and to use the updated Go compiler in 1.20.7 or 1.19.12. There are no known workarounds for this issue.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
August 3, 2023	Reserved	Reserved by GitHub_M
August 8, 2023	Published	Published (CNA: GitHub_M)
September 1, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2023-39533 (libp2p go-libp2p). Public exploit reference added.

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
libp2p	go-libp2p	—	< 0.27.8	—

Weaknesses

CWE-770

References (9)

https://github.com/golang/go/commit/2350afd2e8ab054390e284c95d5b089c142db017 [Not Applicable, Patch]
https://github.com/golang/go/issues/61460 [Issue Tracking, Not Applicable, Vendor Advisory]
https://github.com/libp2p/go-libp2p/commit/0cce607219f3710addc7e18672cffd1f1d912fbb [Patch]
https://github.com/libp2p/go-libp2p/commit/445be526aea4ee0b1fa5388aa65d32b2816d3a00 [Patch]
https://github.com/libp2p/go-libp2p/commit/e30fcf7dfd4715ed89a5e68d7a4f774d3b9aa92d [Patch]
https://github.com/libp2p/go-libp2p/pull/2454 [Exploit, Patch, Vendor Advisory]
https://github.com/libp2p/go-libp2p/security/advisories/GHSA-876p-8259-xjgg [Patch, Vendor Advisory]
https://github.com/quic-go/quic-go/pull/4012 [Patch, Third Party Advisory]
https://nrdax.com/techniques/NRDAX-T0205-pre-handshake-crypto-cpu-burn

Authoritative record: CVE-2023-39533 at cve.org

Vendors: libp2p

Weaknesses: CWE-770

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2023-39533 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.