CVE-2026-40165

highPriorität · verfolgen · 0EPSS 0.005 · 43. PerzentilEUUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
0.50% (43rd) EPSS
CVSS 8.7 · high
Is it mine?
4 products
Prüfe deine Angriffsfläche
Who says so?
3 sources
cnnvd · enisa_euvd · osv

EPSS · bewertet 2026-10-27

authentik is an open-source identity provider. Versions 2025.12.4 and prior, and versions 2026.2.0-rc1 through 2026.2.2 were vulnerable to Authentication Bypass through SAML NameID XML Comment Injection. Due to how authentik extracted the NameID value from a SAML assertion, it was possible for an attacker to trick authentik into only seeing a part of the NameID value, potentially allowing an attacker to gain access to other accounts. This issue could be exploited on an authentik instance with a SAML Source, where the attacker had an account on the SAML Source and the ability to modify their NameID value (commonly username or E-mail), and XML Signing was enabled. The attacker could modify the SAML assertion given to authentik by injecting a comment within the NameID value, which effectively truncated the NameID value to the snippet before the comment, and gave the attacker access to any user account. This issue has been fixed in versions 2025.12.5 and 2026.2.3.

01

cvss

Technischer Schweregrad, 0–10. Eine Zeile je Quelle.

8.7
010

Basiswert 0–10 · höher = schwerwiegender · Vektor überfahren zum Auflösen

v3.18.7highCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:Nsecondary · ENISA EU
v3.18.7highCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:Nsecondary · security-advisories@github.comAusnutzbarkeit 2.2 · Auswirkung 5.8
v3.18highCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N/E:Usecondary · CVSS-BT (t0sche)
02

SSVC

Eine Handlungsentscheidung — aus Ausnutzung und Auswirkung.

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS
03

schwächen

Die CWE-Schwächeklassen, zu denen dies gehört.

CWE-287USCWE-436USCWE-91US
04

betroffene Produkte (4)

Betroffene Produkte und Versionsbereiche.

05

Advisories (1)

Hersteller- und Ökosystem-Meldungen dazu.

  • BIT-authentik-2026-40165authentik: SAML NameID XML Comment Injection Enables Authentication Bypass via Identifier Truncation2026-05-25vendor · osvUS

    authentik is an open-source identity provider. Versions 2025.12.4 and prior, and versions 2026.2.0 through 2026.2.2 were vulnerable to Authentication Bypass through SAML NameID XML Comment Injection. Due to how authentik extracted the NameID value from a SAML assertion, it was possible for an attacker to trick authentik into only seeing a part of the NameID value, potentially allowing an attacker to gain access to other accounts. This issue could be exploited on an authentik instance with a SAML Source, where the attacker had an account on the SAML Source and the ability to modify their NameID value (commonly username or E-mail), and XML Signing was enabled. The attacker could modify the SAML assertion given to authentik by injecting a comment within the NameID value, which effectively truncated the NameID value to the snippet before the comment, and gave the attacker access to any user account. This issue has been fixed in versions 2025.12.5 and 2026.2.3.

06

auch bekannt als (3)

Weitere Namen und Kennungen dieser Entität.

07

quellen

Welche Quellen diesen Datensatz belegen und wann.

cnnvdenisa_euvdosvNVDCVE.orgMITRE
veröffentlicht 2026-05-21geändert 2026-07-23
08

Referenzen (8)

Externe Belege — Patches, Meldungen, Analysen.

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