Description
The XmlSecLibs library as used in the saml2 library in SimpleSAMLphp before 1.15.3 incorrectly verifies signatures on SAML assertions, allowing a remote attacker to construct a crafted SAML assertion on behalf of an Identity Provider that would pass as cryptographically valid, thereby allowing them to impersonate a user from that Identity Provider, aka a key confusion issue.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | simplesamlphp | 1.15.3-1 | — |
| Debian 12 | simplesamlphp | 1.15.3-1 | — |
| Debian 9 | simplesamlphp | 1.14.11-1+deb9u1 | DSA-4127-1 |
| Debian 8 | simplesamlphp | 1.13.1-2+deb8u1 | DSA-4127-1 |
| Debian 7 | simplesamlphp | 1.9.2-1+deb7u3 | DLA-1298-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 16.04 LTS | simplesamlphp | No fix yet | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Packagist | simplesamlphp/saml2 | < 1.10.5 | 1.10.5 | GHSA-923w-2xv2-7pr8 |
| Packagist | simplesamlphp/saml2 | >= 2.0, < 2.3.7 | 2.3.7 | GHSA-923w-2xv2-7pr8 |
| Packagist | simplesamlphp/saml2 | >= 3.0, < 3.1.3 | 3.1.3 | GHSA-923w-2xv2-7pr8 |
Advisories 2
- DSA-4127-1 simplesamlphp - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-1298-1 simplesamlphp - security update Debian Security (DSA / DLA) · Mar 9, 2026