CVE-2026-15556: Picketlink-federation: picketlink saml 2.0 auth bypass via missing assertions
Vulnerability summary
CVE-2026-15556 is a high (CVSS 8.1) vulnerability. EPSS estimates a 0.30% chance of exploitation in the next 30 days, higher than 22.9% of scored vulnerabilities.
Not severe (CVSS 8.1, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 3Timeline
- 11-08-2026PublishedVulnerability first disclosed.
- 01-11-2026Last modifiedVulnerability information updated.
Description
A flaw was found in Picketlink's SP signature validation; a SAML response containing zero assertion elements matching the signature check can allow an attacker to forge a SAML response and auth as any principal with any roles on the protected application.
CVSS metrics
2 scores · 2 sources · 1 version- NVDNIST8.1HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
EPSS trend
Probability
0.30%
Chance of exploitation in the next 30 days
Percentile
23%
Versus all other CVEs
30-day change
Increase +0.06 pp
From 0.24% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
No affected systems are recorded for this record.
Known conditions: network-reachable, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.