CVE-2026-41577

MEDIUMCVSS 6.9/10EPSS 0.17%

Last modified

CVE-2026-41577 is a medium-severity vulnerability rated 6.9/10 on the CVSS scale. authentik is an open-source identity provider. Prior to versions 2025.12.5 and 2026.2.3, the SAML source response processor (ResponseProcessor.parse()) does not validate the Conditions element on assertions. EPSS estimates a 0.17% chance of exploitation in the next 30 days.

Description

authentik is an open-source identity provider. Prior to versions 2025.12.5 and 2026.2.3, the SAML source response processor (ResponseProcessor.parse()) does not validate the Conditions element on assertions. NotBefore, NotOnOrAfter, and AudienceRestriction are all ignored. This allows replay of expired assertions and acceptance of assertions intended for other service providers. This issue has been patched in versions 2025.12.5 and 2026.2.3.

Metrics

CVSS 3.1
7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

CVSS 4.0
6.9/10

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/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:X/V:X/RE:X/U:X

EPSS Probability
0.17%

6.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
GoauthentikAuthentik< 2025.12.5
GoauthentikAuthentik>= 2026.2.0, < 2026.2.3

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-41577?
authentik is an open-source identity provider. Prior to versions 2025.12.5 and 2026.2.3, the SAML source response processor (ResponseProcessor.parse()) does not validate the Conditions element on assertions. NotBefore, NotOnOrAfter, and AudienceRestriction are all ignored. This allows replay of expired assertions and acceptance of assertions intended for other service providers. This issue has been patched in versions 2025.12.5 and 2026.2.3.
How severe is CVE-2026-41577?
CVE-2026-41577 has a CVSS score of 6.9/10 (MEDIUM severity). The EPSS model estimates a 0.17% probability of exploitation in the next 30 days.
How do I fix CVE-2026-41577?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-41577?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST