Vulnerability in Typo3 Oidc

CVE-2025-24856

An issue was discovered in the oidc (aka OpenID Connect Authentication) extension before 4.0.0 for TYPO3. The account linking logic allows a pre-hijacking attack, leading to Account Takeover. The attack can only be exploited if the following requirements are met: (1) an attacker can anticipate the e-mail address of the user, (2) an attacker can register a public frontend user account using that e-mail address before the user's first OIDC login, and (3) the IDP returns an email field containing the e-mail address of the user,

EPSS: 0.002 (6.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.2 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-24856?
CVE-2025-24856 is a medium-severity vulnerability in Typo3 Oidc, classified under CWE-348. CVSS score: 4.2/10. Published 2025-03-16.
How severe is CVE-2025-24856?
Medium severity. CVSS v3 base score is 4.2 out of 10.
Is CVE-2025-24856 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.