CVE-2026-53424

Published: Ago 20, 2026 Last Modified: Ago 20, 2026
ExploitDB:
Other exploit source:
Google Dorks:
CRITICAL 9,1
Source: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: none
Confidentiality: N/A
Integrity: N/A
Availability: N/A

Description

AI Translation Available

Authentication Bypass by Capture-replay vulnerability in dropbox samly allows an attacker to authenticate as the subject of a captured SAML assertion by resubmitting it.

Samly.Helper.decode_idp_auth_resp/3 in lib/samly/helper.ex calls esaml_sp:validate_assertion/2, whose default duplicate detector is a no-op. The /3 arity accepting a DuplicateFun exists in esaml and implements the check, but Samly never calls it and offers no configuration to supply one, so the SAML 2.0 Web Browser SSO Profile requirement that a bearer assertion be used once is unenforced. An attacker holding a valid SAMLResponse obtained from the network, from browser history, or from logs can submit the identical bytes repeatedly until the assertion's NotOnOrAfter passes, each time establishing a session as the assertion's subject.

This issue affects samly: from 0.3.0 onward.

294

Authentication Bypass by Capture-replay

Incomplete
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Access Control
Potential Impacts:
Gain Privileges Or Assume Identity
Applicable Platforms
All platforms may be affected
Likelihood of Exploit: High
View CWE Details
https://cna.erlef.org/cves/CVE-2026-53424.html
https://cna.erlef.org/cves/CVE-2026-53424.html
https://osv.dev/vulnerability/EEF-CVE-2026-53424
https://osv.dev/vulnerability/EEF-CVE-2026-53424