CVE-2026-15556

HIGHPre-NVD 8.18.1—
EchelonGraph scoreMEDIUM confidence

Score 8.1 from GitHub Security Advisory (severity: HIGH) published 2026-08-11. A secondary CVSS source baseline 8.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
8.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 8.1Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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 v3
8.1
EG Score
8.1HIGHmedium confidence
EG Risk
37
EG Risk 37/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity81% × 45%
Exploitation0% × 40%
Automatability0% × 15%
CISA SSVC: Track at low or medium mission impact; Track* at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.2%
EPSS %ILE
13th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

August 11, 2026

Last Modified

September 25, 2026

Advisory Details (2)

Auto-updated Aug 11, 2026
Patch available. Sources: redhat.
redhat

2483121 – (CVE-2026-15556) CVE-2026-15556 picketlink-federation: picketlink SAML 2.0 auth bypass via missing assertions

https://bugzilla.redhat.com/show_bug.cgi?id=2483121
redhat Patch Available

CVE-2026-15556 - Red Hat Customer Portal

Affected: Red Hat Enterprise Linux 8 or OpenShift Container Platform 4, is affected by this vulnerability and a fix may be released to a

https://access.redhat.com/security/cve/CVE-2026-15556

Vendor Advisories for CVE-2026-15556(5)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(4)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhateap7-wildfly-0:7.4.25-2.GA_redhat_00001.1.el7eap2026-08-11redhat
redhatorg.picketlink/picketlink-federation:2.5.5.SP12-redhat-000162026-08-11redhat
redhateap7-wildfly-0:7.4.25-2.GA_redhat_00001.1.el8eap2026-08-11redhat
redhateap7-wildfly-0:7.4.25-2.GA_redhat_00001.1.el9eap2026-08-11redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 27× in last 7d / 147× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 298 total refreshes for this CVE.

  1. 2026-10-04 23:21 UTCEPSS rescore
  2. 2026-10-04 22:47 UTCVendor advisory
  3. 2026-10-04 22:47 UTCGHSA enrichment
  4. 2026-10-04 10:12 UTCVendor advisory
  5. 2026-10-04 10:12 UTCGHSA enrichment
  6. 2026-10-03 21:35 UTCEG score recompute
  7. 2026-10-03 21:35 UTCVendor advisory
  8. 2026-10-03 21:35 UTCGHSA enrichment
  9. 2026-10-03 14:25 UTCEPSS rescore
  10. 2026-10-02 22:30 UTCEG score recompute
  11. 2026-10-02 22:30 UTCVendor advisory
  12. 2026-10-02 22:29 UTCGHSA enrichment
  13. 2026-10-02 09:14 UTCEG score recompute
  14. 2026-10-02 09:14 UTCVendor advisory
  15. 2026-10-02 09:14 UTCGHSA enrichment
  16. 2026-10-01 19:49 UTCEPSS rescore
  17. 2026-10-01 10:53 UTCVendor advisory
  18. 2026-10-01 10:53 UTCGHSA enrichment
  19. 2026-09-30 22:22 UTCEG score recompute
  20. 2026-09-30 22:22 UTCVendor advisory
  21. 2026-09-30 22:22 UTCGHSA enrichment
  22. 2026-09-30 15:02 UTCEPSS rescore
  23. 2026-09-29 15:20 UTCEPSS rescore
  24. 2026-09-29 05:19 UTCEG score recompute
  25. 2026-09-29 05:19 UTCVendor advisory
Show 75 more
  1. 2026-09-29 05:19 UTCGHSA enrichment
  2. 2026-09-28 13:51 UTCEPSS rescore
  3. 2026-09-28 02:21 UTCEG score recompute
  4. 2026-09-28 02:21 UTCVendor advisory
  5. 2026-09-28 02:21 UTCGHSA enrichment
  6. 2026-09-27 13:47 UTCEPSS rescore
  7. 2026-09-27 11:03 UTCEG score recompute
  8. 2026-09-27 11:03 UTCVendor advisory
  9. 2026-09-27 11:03 UTCGHSA enrichment
  10. 2026-09-26 15:58 UTCEPSS rescore
  11. 2026-09-25 13:24 UTCEG score recompute
  12. 2026-09-25 13:24 UTCVendor advisory
  13. 2026-09-25 13:24 UTCGHSA enrichment
  14. 2026-09-25 13:04 UTCEG score recompute
  15. 2026-09-25 13:04 UTCVendor advisory
  16. 2026-09-25 13:04 UTCGHSA enrichment
  17. 2026-09-25 03:57 UTCEG score recompute
  18. 2026-09-25 03:57 UTCVendor advisory
  19. 2026-09-25 03:57 UTCGHSA enrichment
  20. 2026-09-24 01:54 UTCEG score recompute
  21. 2026-09-24 01:54 UTCVendor advisory
  22. 2026-09-24 01:54 UTCGHSA enrichment
  23. 2026-09-23 13:34 UTCVendor advisory
  24. 2026-09-23 13:34 UTCGHSA enrichment
  25. 2026-09-23 00:03 UTCEG score recompute
  26. 2026-09-23 00:03 UTCVendor advisory
  27. 2026-09-23 00:03 UTCGHSA enrichment
  28. 2026-09-22 11:43 UTCVendor advisory
  29. 2026-09-22 11:43 UTCGHSA enrichment
  30. 2026-09-21 23:23 UTCEG score recompute
  31. 2026-09-21 23:23 UTCVendor advisory
  32. 2026-09-21 23:23 UTCGHSA enrichment
  33. 2026-09-21 11:02 UTCEG score recompute
  34. 2026-09-21 11:02 UTCVendor advisory
  35. 2026-09-21 11:02 UTCGHSA enrichment
  36. 2026-09-20 19:43 UTCVendor advisory
  37. 2026-09-20 19:43 UTCGHSA enrichment
  38. 2026-09-20 02:01 UTCEG score recompute
  39. 2026-09-20 02:01 UTCVendor advisory
  40. 2026-09-20 02:01 UTCGHSA enrichment
  41. 2026-09-19 13:41 UTCVendor advisory
  42. 2026-09-19 13:41 UTCGHSA enrichment
  43. 2026-09-19 01:21 UTCEG score recompute
  44. 2026-09-19 01:21 UTCVendor advisory
  45. 2026-09-19 01:21 UTCGHSA enrichment
  46. 2026-09-18 19:27 UTCEPSS rescore
  47. 2026-09-18 13:00 UTCVendor advisory
  48. 2026-09-18 13:00 UTCGHSA enrichment
  49. 2026-09-18 00:28 UTCEG score recompute
  50. 2026-09-18 00:28 UTCVendor advisory
  51. 2026-09-18 00:28 UTCGHSA enrichment
  52. 2026-09-17 23:43 UTCEG score recompute
  53. 2026-09-17 23:43 UTCVendor advisory
  54. 2026-09-17 23:43 UTCGHSA enrichment
  55. 2026-09-17 19:28 UTCEG score recompute
  56. 2026-09-17 19:28 UTCVendor advisory
  57. 2026-09-17 19:28 UTCGHSA enrichment
  58. 2026-09-17 18:29 UTCEG score recompute
  59. 2026-09-17 18:29 UTCVendor advisory
  60. 2026-09-17 18:29 UTCGHSA enrichment
  61. 2026-09-17 14:03 UTCVendor advisory
  62. 2026-09-17 14:03 UTCGHSA enrichment
  63. 2026-09-17 00:39 UTCEG score recompute
  64. 2026-09-17 00:39 UTCVendor advisory
  65. 2026-09-17 00:39 UTCGHSA enrichment
  66. 2026-09-16 14:07 UTCEPSS rescore
  67. 2026-09-16 05:14 UTCEPSS rescore
  68. 2026-09-16 02:19 UTCVendor advisory
  69. 2026-09-16 02:19 UTCGHSA enrichment
  70. 2026-09-15 13:30 UTCEG score recompute
  71. 2026-09-15 13:30 UTCVendor advisory
  72. 2026-09-15 13:30 UTCGHSA enrichment
  73. 2026-09-14 22:48 UTCVendor advisory
  74. 2026-09-14 22:48 UTCGHSA enrichment
  75. 2026-09-14 09:17 UTCVendor advisory

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Frequently asked(5)

What is CVE-2026-15556?
CVE-2026-15556 is a high vulnerability published on August 11, 2026. 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.
When was CVE-2026-15556 disclosed?
CVE-2026-15556 was first published on August 11, 2026, with the most recent update on September 25, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-15556 actively exploited?
CVE-2026-15556 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (13th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-15556?
CVE-2026-15556 has a CVSS base score of 8.1 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-15556?
A fix for CVE-2026-15556 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-15556 are linked in the Vendor Advisories panel on this page.

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