CVE ID :CVE-2026-55735<\/p>\n
Published : Aug. 1, 2026, 7:16 p.m. | 33\u00a0minutes ago<\/p>\n
Description :Improper Verification of Cryptographic Signature in ueberauth guardian allows an unauthenticated attacker to revoke a victim’s session with a forged token.<\/p>\n
Guardian.revoke\/3 in lib\/guardian.ex decodes the supplied token with peek\/1, which performs no signature verification (it only base64-decodes the JWT header and payload). The resulting unverified claims are forwarded directly to the configured token module’s revoke callback and the implementation’s on_revoke callback, a state-mutating sink. The sibling operations refresh\/2 and exchange\/4 both call decode_and_verify first, so the signature is checked before anything acts on the claims; revoke\/3 is the only state-mutating path that acts on claims without verifying the signature.<\/p>\n
An attacker who knows or guesses a victim’s identifying claim values (jti, sub) can forge a JWT carrying those claims, sign it with an arbitrary key, and submit it to any endpoint that funnels a caller-supplied token into Guardian.revoke\/3 (the standard logout \/ session-revocation pattern). When the token module mutates state keyed by the claims (whitelist deletion or blacklist insertion, for example a GuardianDb-style store), the victim’s legitimate session is evicted. This is an unauthenticated session-revocation denial of service; the attacker never needs the signing secret.<\/p>\n
This issue affects guardian: from 1.0.0 before 2.4.1.<\/p>\n
Severity: 8.2 | HIGH<\/p>\n
Visit the link for more details, such as CVSS details, affected products, timeline, and more…\u00a0<\/p>\n","protected":false},"excerpt":{"rendered":"
CVE ID :CVE-2026-55735 Published : Aug. 1, 2026, 7:16 p.m. | 33\u00a0minutes ago Description :Improper Verification of Cryptographic Signature in ueberauth guardian allows an unauthenticated attacker to revoke a victim’s session with a forged token. Guardian.revoke\/3 in lib\/guardian.ex decodes the supplied token with peek\/1, which performs no signature verification (it only base64-decodes the JWT header …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[26],"tags":[],"class_list":["post-82860","post","type-post","status-publish","format-standard","hentry","category-vulnerability"],"_links":{"self":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts\/82860","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/comments?post=82860"}],"version-history":[{"count":0,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts\/82860\/revisions"}],"wp:attachment":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/media?parent=82860"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/categories?post=82860"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/tags?post=82860"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}