8.6

CVE-2025-27773: simplesamlphp saml2

CVSS: 8.6v3.1HighDeferred
AliasesUBUNTU-CVE-2025-27773DEBIAN-CVE-2025-27773DLA-4161-1
Published 11-03-2025Last modified 09-05-2025
Open JSON

Vulnerability summary

CVE-2025-27773 is a high (CVSS 8.6) vulnerability in simplesamlphp saml2. EPSS estimates a 0.41% chance of exploitation in the next 30 days, higher than 34.7% of scored vulnerabilities.

Overall risk
34/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.6/10
010
High · v3.1 (CVE.org)
EPSS score
0.41%
0%100%
Low · +0.03 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 1 · Related 1
USN-8770-1

Timeline

  1. 11-03-2025
    PublishedVulnerability first disclosed.
  2. 09-05-2025
    Last modifiedVulnerability information updated.

Description

The SimpleSAMLphp SAML2 library is a PHP library for SAML2 related functionality. Prior to versions 4.17.0 and 5.0.0-alpha.20, there is a signature confusion attack in the HTTPRedirect binding. An attacker with any signed SAMLResponse via the HTTP-Redirect binding can cause the application to accept an unsigned message. Versions 4.17.0 and 5.0.0-alpha.20 contain a fix for the issue.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.41%

Chance of exploitation in the next 30 days

Percentile

35%

Versus all other CVEs

30-day change

+0.03 pp

From 0.39% on 22-09-2026

22-09-202622-10-2026
EPSS score
0.41%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Debian1 product
  • simplesamlphp< 1.19.7-1+deb12u2 | < 1.19.7-2 | < 1.19.0-1+deb11u2
Simplesamlphp1 product
  • saml2< 4.17.0 | ≥ 5.0.0-alpha.1, < 5.0.0-alpha.20
Ubuntu1 product
  • simplesamlphp< 1.14.0-1ubuntu2+esm1 | < 1.15.3-1ubuntu0.1~esm1 | < 1.18.4-1ubuntu0.1~esm1 | < 1.19.1-1.1ubuntu0.1~esm1 | < 1.19.7-1+deb12u1ubuntu0.1 | All versions (No fix recorded)

3 vendors · 3 products

References

9 links