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%CVSS: 8.1Exploit: None knownExposed: 0

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
8.1(medium)
EG Risk
37(Track)
EG Risk 37/100SSVC: Track

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%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
15%
KEV
Not listed

Published

August 11, 2026

Last Modified

September 18, 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(3)

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 / EcosystemFixed in / PatchReleasedSource
redhateap7-wildfly-0:7.4.25-2.GA_redhat_00001.1.el7eap2026-08-11redhat
redhatpicketlink-federation2026-08-11redhat
redhateap7-wildfly-0:7.4.25-2.GA_redhat_00001.1.el9eap2026-08-11redhat
redhateap7-wildfly-0:7.4.25-2.GA_redhat_00001.1.el8eap2026-08-11redhat

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.

Additional Vendor Advisories

(2)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 46× in last 7d / 166× 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 231 total refreshes for this CVE.

  1. 2026-09-19 01:21 UTCEG score recompute
  2. 2026-09-19 01:21 UTCVendor advisory
  3. 2026-09-19 01:21 UTCGHSA enrichment
  4. 2026-09-18 19:27 UTCEPSS rescore
  5. 2026-09-18 13:00 UTCVendor advisory
  6. 2026-09-18 13:00 UTCGHSA enrichment
  7. 2026-09-18 00:28 UTCEG score recompute
  8. 2026-09-18 00:28 UTCVendor advisory
  9. 2026-09-18 00:28 UTCGHSA enrichment
  10. 2026-09-17 23:43 UTCEG score recompute
  11. 2026-09-17 23:43 UTCVendor advisory
  12. 2026-09-17 23:43 UTCGHSA enrichment
  13. 2026-09-17 19:28 UTCEG score recompute
  14. 2026-09-17 19:28 UTCVendor advisory
  15. 2026-09-17 19:28 UTCGHSA enrichment
  16. 2026-09-17 18:29 UTCEG score recompute
  17. 2026-09-17 18:29 UTCVendor advisory
  18. 2026-09-17 18:29 UTCGHSA enrichment
  19. 2026-09-17 14:03 UTCVendor advisory
  20. 2026-09-17 14:03 UTCGHSA enrichment
  21. 2026-09-17 00:39 UTCEG score recompute
  22. 2026-09-17 00:39 UTCVendor advisory
  23. 2026-09-17 00:39 UTCGHSA enrichment
  24. 2026-09-16 14:07 UTCEPSS rescore
  25. 2026-09-16 05:14 UTCEPSS rescore
Show 75 more
  1. 2026-09-16 02:19 UTCVendor advisory
  2. 2026-09-16 02:19 UTCGHSA enrichment
  3. 2026-09-15 13:30 UTCEG score recompute
  4. 2026-09-15 13:30 UTCVendor advisory
  5. 2026-09-15 13:30 UTCGHSA enrichment
  6. 2026-09-14 22:48 UTCVendor advisory
  7. 2026-09-14 22:48 UTCGHSA enrichment
  8. 2026-09-14 09:17 UTCVendor advisory
  9. 2026-09-14 09:17 UTCGHSA enrichment
  10. 2026-09-13 20:57 UTCEG score recompute
  11. 2026-09-13 20:57 UTCVendor advisory
  12. 2026-09-13 20:57 UTCGHSA enrichment
  13. 2026-09-13 16:46 UTCEPSS rescore
  14. 2026-09-13 08:36 UTCVendor advisory
  15. 2026-09-13 08:36 UTCGHSA enrichment
  16. 2026-09-12 20:16 UTCEG score recompute
  17. 2026-09-12 20:16 UTCVendor advisory
  18. 2026-09-12 20:16 UTCGHSA enrichment
  19. 2026-09-12 15:00 UTCEPSS rescore
  20. 2026-09-12 07:56 UTCVendor advisory
  21. 2026-09-12 07:56 UTCGHSA enrichment
  22. 2026-09-11 19:33 UTCEG score recompute
  23. 2026-09-11 19:33 UTCVendor advisory
  24. 2026-09-11 19:33 UTCGHSA enrichment
  25. 2026-09-11 14:52 UTCEPSS rescore
  26. 2026-09-11 09:36 UTCEPSS rescore
  27. 2026-09-11 07:13 UTCVendor advisory
  28. 2026-09-11 07:13 UTCGHSA enrichment
  29. 2026-09-10 18:53 UTCEG score recompute
  30. 2026-09-10 18:53 UTCVendor advisory
  31. 2026-09-10 18:53 UTCGHSA enrichment
  32. 2026-09-10 09:34 UTCEPSS rescore
  33. 2026-09-10 06:31 UTCVendor advisory
  34. 2026-09-10 06:31 UTCGHSA enrichment
  35. 2026-09-09 18:11 UTCVendor advisory
  36. 2026-09-09 18:11 UTCGHSA enrichment
  37. 2026-09-09 05:47 UTCEG score recompute
  38. 2026-09-09 05:47 UTCVendor advisory
  39. 2026-09-09 05:47 UTCGHSA enrichment
  40. 2026-09-08 22:00 UTCEPSS rescore
  41. 2026-09-08 07:19 UTCVendor advisory
  42. 2026-09-08 07:19 UTCGHSA enrichment
  43. 2026-09-07 17:07 UTCEG score recompute
  44. 2026-09-07 17:07 UTCVendor advisory
  45. 2026-09-07 17:07 UTCGHSA enrichment
  46. 2026-09-07 16:01 UTCEPSS rescore
  47. 2026-09-06 16:05 UTCEG score recompute
  48. 2026-09-06 16:05 UTCVendor advisory
  49. 2026-09-06 16:04 UTCGHSA enrichment
  50. 2026-09-06 13:47 UTCEPSS rescore
  51. 2026-09-06 03:42 UTCEG score recompute
  52. 2026-09-06 03:42 UTCVendor advisory
  53. 2026-09-06 03:42 UTCGHSA enrichment
  54. 2026-09-05 15:22 UTCVendor advisory
  55. 2026-09-05 15:22 UTCGHSA enrichment
  56. 2026-09-05 01:47 UTCEG score recompute
  57. 2026-09-05 01:47 UTCVendor advisory
  58. 2026-09-05 01:47 UTCGHSA enrichment
  59. 2026-09-04 08:19 UTCEG score recompute
  60. 2026-09-04 08:19 UTCVendor advisory
  61. 2026-09-04 08:19 UTCGHSA enrichment
  62. 2026-09-04 05:06 UTCEPSS rescore
  63. 2026-09-03 16:36 UTCVendor advisory
  64. 2026-09-03 16:36 UTCGHSA enrichment
  65. 2026-09-03 01:57 UTCEG score recompute
  66. 2026-09-03 01:57 UTCVendor advisory
  67. 2026-09-03 01:57 UTCGHSA enrichment
  68. 2026-09-02 14:11 UTCEPSS rescore
  69. 2026-09-02 02:01 UTCEG score recompute
  70. 2026-09-02 02:01 UTCVendor advisory
  71. 2026-09-02 02:00 UTCGHSA enrichment
  72. 2026-09-01 13:53 UTCEPSS rescore
  73. 2026-09-01 13:31 UTCVendor advisory
  74. 2026-09-01 13:31 UTCGHSA enrichment
  75. 2026-09-01 00:26 UTCVendor advisory

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 in the National Vulnerability Database on August 11, 2026, with the most recent update on September 18, 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% probability of exploitation in the next 30 days, which ranks it in the top 84.8% of all scored CVEs.
What is the CVSS score of CVE-2026-15556?
CVE-2026-15556 has a CVSS v3 base score of 8.1 (NVD).
How do I remediate CVE-2026-15556?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-15556, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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