9.3

CVE-2026-42849: authentik: Reflected XSS in SFE AutosubmitStage allows IDP account takeover

Analyzed
Published 02-06-2026Last modified 03-06-2026

Vulnerability summary

CVE-2026-42849 is a critical (CVSS 9.3) vulnerability in goauthentik authentik. EPSS estimates a 0.33% chance of exploitation in the next 30 days, higher than 25.8% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 9.3 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 0% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
9.3/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.33%
0%100%
Low · -0.15 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 02-06-2026
    PublishedVulnerability first disclosed.
  2. 03-06-2026
    Last modifiedVulnerability information updated.

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 metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.33%

Chance of exploitation in the next 30 days

Percentile

26%

Versus all other CVEs

30-day change

Decrease -0.15 pp

From 0.47% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, user interaction (CVSS vector). Other conditions: not stated in public data.

Goauthentik1 product
  • authentik< 2026.2.3 | < 2025.12.5 | ≥ 2026.2.0, < 2026.2.3

1 vendor · 1 product

References

1 links