{"id":"CVE-2023-39533","aliases":["GHSA-876p-8259-xjgg","GO-2023-2000"],"url":"https://o3.security/vulnerability/CVE-2023-39533","summary":"libp2p nodes vulnerable to attack using large RSA keys","details":"### Impact\nA 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.\nTo prevent this attack, go-libp2p now restricts RSA keys to <= 8192 bits.\n\n### Patches\nUsers should upgrade their go-libp2p versions to >=v0.27.8, >= v0.28.2, or >=v0.29.1\nTo protect your application, it's necessary to update to these patch releases **AND** to use the updated Go compiler (1.20.7 or 1.19.12, respectively)\n\n### Workarounds\nThere are no known workarounds\n\n### References\nThe Golang crypto/tls package also had this vulnerability (\"verifying certificate chains containing large RSA keys is slow” https://github.com/golang/go/issues/61460)\nFix in golang/go crypto/tls: https://github.com/golang/go/commit/2350afd2e8ab054390e284c95d5b089c142db017\nFix in quic-go https://github.com/quic-go/quic-go/pull/4012","published":"2023-08-08T18:50:05.418Z","modified":"2026-10-28T02:30:35.281864557Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":{"score":0.01334,"percentile":0.68658,"asOf":"2026-08-14"},"cisaKev":null,"exploitsKnown":1,"affectedPackages":[{"ecosystem":"Go","name":"github.com/libp2p/go-libp2p","fixedVersion":"0.27.8"},{"ecosystem":"Go","name":"github.com/libp2p/go-libp2p","fixedVersion":"0.28.2"},{"ecosystem":"Go","name":"github.com/libp2p/go-libp2p","fixedVersion":"0.29.1"}],"fix":{"url":"https://github.com/golang/go/commit/2350afd2e8ab054390e284c95d5b089c142db017","label":"golang/go@2350afd"},"references":[{"type":"WEB","url":"https://nrdax.com/techniques/NRDAX-T0205-pre-handshake-crypto-cpu-burn"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/39xxx/CVE-2023-39533.json"},{"type":"ADVISORY","url":"https://github.com/libp2p/go-libp2p/security/advisories/GHSA-876p-8259-xjgg"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-39533"},{"type":"REPORT","url":"https://github.com/golang/go/issues/61460"},{"type":"FIX","url":"https://github.com/golang/go/commit/2350afd2e8ab054390e284c95d5b089c142db017"},{"type":"FIX","url":"https://github.com/libp2p/go-libp2p/commit/0cce607219f3710addc7e18672cffd1f1d912fbb"},{"type":"FIX","url":"https://github.com/libp2p/go-libp2p/commit/445be526aea4ee0b1fa5388aa65d32b2816d3a00"},{"type":"FIX","url":"https://github.com/libp2p/go-libp2p/commit/e30fcf7dfd4715ed89a5e68d7a4f774d3b9aa92d"},{"type":"FIX","url":"https://github.com/libp2p/go-libp2p/pull/2454"},{"type":"FIX","url":"https://github.com/quic-go/quic-go/pull/4012"},{"type":"PACKAGE","url":"https://github.com/libp2p/go-libp2p"},{"type":"WEB","url":"https://go.dev/issue/61460"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-28T02:30:35.281864557Z"}}