{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-41263","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-04-18T14:01:46.801Z","datePublished":"2026-04-30T20:39:49.658Z","dateUpdated":"2026-05-01T14:22:40.566Z"},"containers":{"cna":{"title":"Traefik: BasicAuth middleware: timing side-channel vulnerability","problemTypes":[{"descriptions":[{"cweId":"CWE-208","lang":"en","description":"CWE-208: Observable Timing Discrepancy","type":"CWE"}]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"HIGH","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"LOW","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":6.3,"baseSeverity":"MEDIUM","vectorString":"CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:N/SA:N","version":"4.0"}}],"references":[{"name":"https://github.com/traefik/traefik/security/advisories/GHSA-6x2q-h3cr-8j2h","tags":["x_refsource_CONFIRM"],"url":"https://github.com/traefik/traefik/security/advisories/GHSA-6x2q-h3cr-8j2h"},{"name":"https://github.com/traefik/traefik/releases/tag/v2.11.43","tags":["x_refsource_MISC"],"url":"https://github.com/traefik/traefik/releases/tag/v2.11.43"},{"name":"https://github.com/traefik/traefik/releases/tag/v3.6.14","tags":["x_refsource_MISC"],"url":"https://github.com/traefik/traefik/releases/tag/v3.6.14"},{"name":"https://github.com/traefik/traefik/releases/tag/v3.7.0-rc.2","tags":["x_refsource_MISC"],"url":"https://github.com/traefik/traefik/releases/tag/v3.7.0-rc.2"}],"affected":[{"vendor":"traefik","product":"traefik","versions":[{"version":"< 2.11.43","status":"affected"},{"version":">= 3.0.0-beta1, < 3.6.14","status":"affected"},{"version":">= 3.7.0-ea.1, < 3.7.0-rc.2","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-04-30T20:39:49.658Z"},"descriptions":[{"lang":"en","value":"Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.43, 3.6.14, and 3.7.0-rc.2, there is a timing side-channel vulnerability in Traefik's BasicAuth middleware that allows an attacker to enumerate valid usernames through response-time differences. The variable intended to hold a constant-time fallback secret always resolves to an empty string, causing the constant-time comparison to short-circuit in microseconds rather than performing a full bcrypt evaluation. This restores the original timing oracle and makes it possible to distinguish existing users from non-existing ones by measuring authentication response times. This issue has been patched in versions 2.11.43, 3.6.14, and 3.7.0-rc.2."}],"source":{"advisory":"GHSA-6x2q-h3cr-8j2h","discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-05-01T14:22:30.689474Z","id":"CVE-2026-41263","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-05-01T14:22:40.566Z"}}]}}