Vulnerability record · CVE-2026-89043 · published 10 September 2026

CVE-2026-89043: Improper verification of cryptographic signature vulnerability

passport-saml-encrypted through 0.1.13 contains an XML signature wrapping vulnerability where signature verification and assertion extraction use independent XPath lookups with no cross-validation. Attackers holding any validly signed SAML message can prepend a forged unsigned assertion that gets accepted as the verified identity while the genuine signature validates against the original assertion.

9.1 CVSS 4.0 Critical EPSS 0.31% · top 78.7% CWE-347 · Improper verification of cryptographic signature Deferred

9.1CVSS 4.0 base score

0.31%EPSS exploitation probability, 30 days

NoNot in CISA KEV

0Affected product versions listed by NVD

6References

10 Sep 2026Last modified by NVD

Description

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:

References

Link	Tags
https://github.com/krakenjs/passport-saml-encrypted
https://github.com/krakenjs/passport-saml-encrypted/blob/v0.1.13/lib/saml.js#L256
https://github.com/krakenjs/passport-saml-encrypted/blob/v0.1.13/lib/saml.js#L328
https://github.com/krakenjs/passport-saml-encrypted/issues/30
https://www.vulncheck.com/advisories/passport-saml-encrypted-through-0.1.13-xml-signature-wrapping-via-assertion-prepend
https://github.com/krakenjs/passport-saml-encrypted/issues/30

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Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2026-89043), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.