VulnerabilityAnalyzed

CVE-2026-42849

Prior to versions 2025.12.5 and 2026.2.3, due to the implementation of stages in the SFE (Simple Flow Executor) in order to make the interface more compatible with legacy browsers, it was possible to use an XSS exploit in the AutosubmitStage.

CRITICAL 9.3EPSS 0.36%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.36%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

authentik is an open-source identity provider. Prior to versions 2025.12.5 and 2026.2.3, due to the implementation of stages in the SFE (Simple Flow Executor) in order to make the interface more compatible with legacy browsers, it was possible to use an XSS exploit in the AutosubmitStage. This issue has been patched in versions 2025.12.5 and 2026.2.3.

CVSS 3.1: 9.3 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
EPSS: 0.36% probability · 29th percentile
CISA KEV: Not listed
Weakness: CWE-79
Affected: goauthentik/authentik
Source: security-advisories@github.com

References

https://github.com/goauthentik/authentik/security/advisories/GHSA-pgff-5mx8-fqj3Vendor Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.