CVE-2025-24856
TYPO3-EXT-SA-2025-001: Account Takeover in extension "OpenID Connect Authentication" (oidc)
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,
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
4.2
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,
- Record
CVE-2025-24856- CVSS 3.1
- 4.2 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N/E:F/RL:O/RC:C - Weakness
- CWE-348
- Updated
- 2026-11-02
EUVDEUVD-2025-0169
4.2
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,
- Record
EUVD-2025-0169- CVSS 3.1
- 4.2 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N/E:F/RL:O/RC:C - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-hj78-p4h7-m5fv
4.2
TYPO3-EXT-SA-2025-001: Account Takeover in extension "OpenID Connect Authentication" (oidc)
Problem Description
A vulnerability in the account linking logic of the extension allows a pre-hijacking attack leading to Account Takeover. The attack can only be exploited if the following requirements are met:
- An attacker can anticipate the email address of the user.
- An attacker can register a public frontend user account using that email address before the user's first OIDC login.
- The IDP returns the field email containing the email address of the user
Solution
An updated versions 4.0.0 is available from the TYPO3 extension manager, packagist and at https://extensions.typo3.org/extension/download/oidc/4.0.0/zip
Users of the extension are advised to update the extension as soon as possible.
- Record
GHSA-hj78-p4h7-m5fv- CVSS 3.1
- 4.2 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N - Weakness
- CWE-288, CWE-348, CWE-639
- Updated
- 2026-11-02
NVD
4.2
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,
- Record
CVE-2025-24856- CVSS 3.1
- 4.2 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N - Weakness
- CWE-348
- Updated
- 2026-11-02
OSV
4.2
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,
- Record
CVE-2025-24856- CVSS 3.1
- 4.2 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N/E:F/RL:O/RC:C - Weakness
- CWE-348
- Updated
- 2026-11-02
OSVGHSA-hj78-p4h7-m5fv
4.2
TYPO3-EXT-SA-2025-001: Account Takeover in extension "OpenID Connect Authentication" (oidc)
Problem Description
A vulnerability in the account linking logic of the extension allows a pre-hijacking attack leading to Account Takeover. The attack can only be exploited if the following requirements are met:
- An attacker can anticipate the email address of the user.
- An attacker can register a public frontend user account using that email address before the user's first OIDC login.
- The IDP returns the field email containing the email address of the user
Solution
An updated versions 4.0.0 is available from the TYPO3 extension manager, packagist and at https://extensions.typo3.org/extension/download/oidc/4.0.0/zip
Users of the extension are advised to update the extension as soon as possible.
- Record
GHSA-hj78-p4h7-m5fv- CVSS 3.1
- 4.2 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N - Weakness
- CWE-288, CWE-348, CWE-639
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
causal/oidcPackagist |
3.0.0 up to 4.0.0 | 4.0.0 |
causal/oidcPackagist |
3.0.0 up to 4.0.0, plus listed versions v3.0.0 |
4.0.0 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-24856 is a medium vulnerability (CVSS 4.2) in Typo3 Oidc, published January 28, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.18%, the 7th percentile. Fixed in causal/oidc 4.0.0.
References
typo3.org/security/advisory/typo3-ext-sa-2025-001
github.com/xperseguers/t3ext-oidc/commit/877e09f6faf4c87bbb41233112ec7e30d3c902b3
github.com/FriendsOfPHP/security-advisories/blob/master/causal/oidc/CVE-2025-24856.yaml
nvd.nist.gov/vuln/detail/CVE-2025-24856
github.com/advisories/GHSA-hj78-p4h7-m5fv
github.com/CVEProject/cvelistV5/tree/main/cves/2025/24xxx/CVE-2025-24856.json