{"id":"CVE-2026-86219","summary":"Authen::SASL::Perl::DIGEST_MD5 versions before 2.2100 for Perl accept replayed authentication responses via unverified nonce in server_step","details":"Authen::SASL::Perl::DIGEST_MD5 versions before 2.2100 for Perl accept replayed authentication responses via unverified nonce in server_step.\n\nserver_start generates a fresh nonce and sends it in the challenge, and nothing later compares that value against the nonce the client returns. server_step derives the expected digest from the client's own parameters, so a response verifies whenever its digest matches the nonce it carries. The count table it also checks is keyed on the client-supplied nonce and starts empty in each new server object, so a captured first response, carrying `nc=00000001`, passes that too. RFC 2831 defines the nonce in the response as the value the server sent in the preceding challenge.\n\nAn attacker who observes one successful `qop=auth` exchange can replay the captured response against a later session for the same service, host, realm and user, and authenticate as that user without knowing the password.","modified":"2026-09-09T03:47:38.710744366Z","published":"2026-09-06T17:46:30.340Z","database_specific":{"cwe_ids":["CWE-294"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/86xxx/CVE-2026-86219.json","unresolved_ranges":[{"extracted_events":[{"fixed":"2.2100"}],"source":"AFFECTED_FIELD"},{"source":"DESCRIPTION","extracted_events":[{"fixed":"2.2100"}]}],"cna_assigner":"CPANSec"},"references":[{"type":"WEB","url":"https://cpan.org/modules"},{"type":"WEB","url":"https://datatracker.ietf.org/doc/html/rfc2831#section-2.1.2"},{"type":"WEB","url":"https://metacpan.org/release/EHUELS/Authen-SASL-2.2000/source/lib/Authen/SASL/Perl/DIGEST_MD5.pm#L203-222"},{"type":"WEB","url":"https://metacpan.org/release/EHUELS/Authen-SASL-2.2000/source/lib/Authen/SASL/Perl/DIGEST_MD5.pm#L410-414"},{"type":"WEB","url":"https://www.cve.org/CVERecord?id=CVE-2025-40918"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/86xxx/CVE-2026-86219.json"},{"type":"ADVISORY","url":"https://metacpan.org/release/EHUELS/Authen-SASL-2.2100/changes"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-86219"},{"type":"FIX","url":"https://github.com/perl-authen-sasl/perl-authen-sasl/commit/94337367030612842924f697cead29964a96448d.patch"},{"type":"PACKAGE","url":"https://github.com/perl-authen-sasl/perl-authen-sasl"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/perl-authen-sasl/perl-authen-sasl","events":[{"introduced":"0"},{"fixed":"94337367030612842924f697cead29964a96448d"}],"database_specific":{"source":"REFERENCES"}}],"versions":["v2.2000","v2.1900","v2.1800","v2.1700","v2.16","v2.15","v2.14","v2.13","v2.12","v2.11"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-86219.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}