How severe is CVE-2026-42849?

CVE-2026-42849 has a CVSS 3.x base score of 9.3, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2026-42849 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-42849?

CVE-2026-42849 affects Goauthentik Authentik. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-42849?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2026-42849 have an EU (EUVD) identifier?

Yes. CVE-2026-42849 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-34026.

When was CVE-2026-42849 published?

CVE-2026-42849 was published on 2026-06-02 and last updated on 2026-06-17.

CVE-2026-42849

CVE-2026-42849 is a critical-severity vulnerability in Goauthentik Authentik with a CVSS 3.x base score of 9.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Critical (CVSS 3.x base score 9.3)
EPSS exploit prediction: 0% (24th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-34026
Weakness: CWE-79
Affected product: Goauthentik Authentik
Published: 2026-06-02
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2026-42849?: 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 severe is CVE-2026-42849?: CVE-2026-42849 has a CVSS 3.x base score of 9.3, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2026-42849 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-42849?: CVE-2026-42849 affects Goauthentik Authentik. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-42849?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-42849 have an EU (EUVD) identifier?: Yes. CVE-2026-42849 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-34026.
When was CVE-2026-42849 published?: CVE-2026-42849 was published on 2026-06-02 and last updated on 2026-06-17.

References

https://github.com/goauthentik/authentik/security/advisories/GHSA-pgff-5mx8-fqj3

Affected products (1)

cpe:2.3:a:goauthentik:authentik:*:*:*:*:*:*:*:*

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