{"cve":"CVE-2023-29409","nvd":{"published":"2023-08-02T20:15:11.940","modified":"2026-06-17T05:49:59.307","status":"Modified","description":"Extremely large RSA keys in certificate chains can cause a client/server to expend significant CPU time verifying signatures. With fix, the size of RSA keys transmitted during handshakes is restricted to <= 8192 bits. Based on a survey of publicly trusted RSA keys, there are currently only three certificates in circulation with keys larger than this, and all three appear to be test certificates that are not actively deployed. It is possible there are larger keys in use in private PKIs, but we target the web PKI, so causing breakage here in the interests of increasing the default safety of users of crypto/tls seems reasonable.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","score":5.3},"cwes":["CWE-400"],"references":["https://go.dev/cl/515257","https://go.dev/issue/61460","https://groups.google.com/g/golang-announce/c/X0b6CsSAaYI/m/Efv5DbZ9AwAJ","https://pkg.go.dev/vuln/GO-2023-1987","https://security.gentoo.org/glsa/202311-09"],"products":["golang:go"],"source":"nvd","synced_at":"2026-10-19T21:38:35.729974749+00:00"},"epss":{"cve":"CVE-2023-29409","score":0.01601,"percentile":0.75808,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GO-2023-1987","url":"https://osv.dev/vulnerability/GO-2023-1987","summary":"Large RSA keys can cause high CPU usage in crypto/tls","modified":"2026-02-04T03:58:58.871084Z","packages":[{"ecosystem":"Go","name":"stdlib","purl":"pkg:golang/stdlib","ranges":["<1.19.12",">=1.20.0-0 <1.20.7",">=1.21.0-0 <1.21.0-rc.4"],"fixed":["1.19.12","1.20.7","1.21.0-rc.4"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}