GHSA-36h8-r92j-w9vw: SPID.AspNetCore.Authentication (CVE-2025-24894)

The AspNetCore Remote Authenticator for SPID Allows SAML Response Signature Verification Bypass

CVSS 9.1 CriticalCriticalEPSS 0.0061 · 49th percentile

Critical, because:

CVSS score 9.1: 9.0 or more.

Published by the GitHub Advisory Database at 18 Feb 2025, 19:25 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

Package	Ecosystem	Affected	Fixed in
SPID.AspNetCore.Authentication	NuGet	<3.4.0	3.4.0

Identifiers

GHSA-36h8-r92j-w9vw · CVE-2025-24894

Weakness (CWE)

CWE-287 · CWE-290

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

NuGet package SPID.AspNetCore.Authentication versions before 3.4.0 are affected. The library does not verify all signatures in a SAML response, only the first one found, so an attacker who can supply an element carrying a valid signature from a configured identity provider (obtainable from public metadata) can craft a response with arbitrary assertions and impersonate any SPID or CIE user. Upgrade to version 3.4.0 or later.

Written 9 Nov 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
9.1	Critical	3.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N	CNA (GitHub_M)

CISA KEV Not listed.
EPSS 0.0061, the 49th percentile, on 11 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

31 Oct 2026, 15:22 UTC First seen by agentprime
31 Oct 2026, 15:22 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.