7.4High

CVE-2026-89043

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.

What this means for your business

  • An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.
  • FIRST's prediction model gives it a 0.3% chance of attack attempts being seen in the next 30 days, ranking above 21% of all known flaws.

What to do

  1. 1Ask your IT team or provider whether any of your systems use the affected product.
  2. 2If you do, follow the vendor's guidance. No patch reference has been published yet.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

Scoring

CVSS
7.4 (v3.1)
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
CVSS v4
9.1
Weakness
CWE-347
Assigned by
disclosure@vulncheck.com

Dates

Published
2026-09-10
Last modified
2026-09-10
Sources
NVD

References