Skip to main content

Boteraser | Website and Server Security Solutions

🛡️ CVE-2026-42849 — authentik

🔴 CVSS 9.5 — Critical ✅ No Known Exploit CWE-79 OSV
9.5
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

authentik: Reflected XSS in SFE AutosubmitStage allows IDP account takeover

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.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. A user must be tricked into taking some action. The scope is changed, meaning a successful attack can affect components beyond the vulnerable one. Rated impact: confidentiality high, integrity high, availability none.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N

  • Attack vector: Network — reachable from anywhere that can route to the service.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Privileges required: None — an unauthenticated stranger can try it.
  • User interaction: Required — someone has to click, open or visit something.
  • Scope: Changed — a successful attack reaches components beyond the vulnerable one.
  • Confidentiality impact: High — total loss, or loss the attacker controls.
  • Integrity impact: High — total loss, or loss the attacker controls.
  • Availability impact: None.

Weakness class

CVE-2026-42849 is classified as CWE-79: Cross-site Scripting (XSS). User-supplied data is written into a page without escaping, so attacker script runs in the browser of anyone who views it.

Affected software

CVE-2026-42849 is recorded against 1 package.

  • authentik

Timeline and source

Published on 5 June 2026 and last revised on 22 July 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

github.com (Web)
nvd.nist.gov (Web)

Other advisories for this package

authentik has other advisories on record. If you are patching this one, these are worth checking on the same host:

Same weakness in other software

These advisories are the same class of weakness (CWE-79: Cross-site Scripting (XSS)) in other software:

Details

Severity CRITICAL
CVSS Score 9.5
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
CWE CWE-79
Public Exploit ✅ No
Source OSV
Published 2026-06-05
Updated 2026-08-20
Modified 2026-07-22
Fix URL N/A

Affected Packages

Software From version Fixed in
authentik — —

Similar Threats

Exploit Protection

Are you running authentik?

CVE-2026-42849 carries CVSS 9.5 Critical rating. BotEraser checks your installation against this and other known CVE records, and blocks IPs associated with exploit activity.

Check My Site For CVE-2026-42849 →

No credit card required  ·  Results in minutes

ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

Browse related advisories

All advisoriesCVECVE 2026
✓