CVE-2025-24895SAML Response Signature Verification Bypass in CIE.AspNetCore.Authentication
- 9.1CriticalCVSS base score
- 0.61%Exploitation in 30 daysEPSS · top 50% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
Description
CIE.AspNetCore.Authentication is an AspNetCore Remote Authenticator for CIE 3.0. Authentication using Spid and CIE is based on the SAML2 standard which provides two entities: 1. Identity Provider (IDP): the system that authenticates users and provides identity information (SAML affirmation) to the Service Provider, in essence, is responsible for the management of the credentials and identity of users; 2. Service Provider (SP): the system that provides a service to the user and relies on the Identity Provider to authenticate the user, receives SAML assertions from the IdP to grant access to resources. The library cie-aspnetcore refers to the second entity, the SP, and implements the validation logic of SAML assertions within SAML responses. In affected versions there is no guarantee that the first signature refers to the root object, it follows that if an attacker injects an item signed as the first element, all other signatures will not be verified. The only requirement is to have an XML element legitimately signed by the IdP, a condition that is easily met using the IdP's public metadata. An attacker could create an arbitrary SAML response that would be accepted by SPs using vulnerable SDKs, allowing him to impersonate any Spid and/or CIE user. This issue has been addressed in version 2.1.0 and all users are advised to upgrade. There are no known workarounds for this vulnerability.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. CISA's SSVC rates its exploitation: a proof of concept is public.
Timeline
ID reserved
By GitHub_M
- 22 days later
· 22 days later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Critical9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
| NVDNVD · Deferred | 3.1 | Critical9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
- EPSS (exploitation in 30 days)
- 0.61% · top 50% of all CVEs (13 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.1.
Affected products
- affected < 2.1.0
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- NuGetCIE.AspNetCore.AuthenticationGHSA-vq63-8f72-f486 (opens in a new tab)
References
References1
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2025-4791 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-vq63-8f72-f486 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2025-24895)Record last updated .