CVE-2026-15826

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-15. A secondary CVSS source baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this weekElevated
9.8EG
EchelonGraph verdictPlan mitigationSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 3.9%CVSS: 9.8Exploit: Elevated riskExposed services: Not assessed

No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.

The User Profile Builder plugin for WordPress is vulnerable to Authentication Bypass via Type Confusion in versions up to, and including, 3.16.4. This is due to the wppb_log_in_user() function calling absint() on the return value of wp_insert_user() before performing an is_wp_error() check — when a registration is submitted with a 61–70 character username, WordPress core rejects it with a WP_Error object, but absint() coerces that object to the integer 1 before the error check can short-circuit execution, causing the plugin to bind and return a transient-backed autologin nonce tied to user ID 1. This makes it possible for unauthenticated attackers to log in as the site's Administrator account (user ID 1), resulting in full administrative takeover of the site.

CVSS v3
9.8
EG Score
9.8CRITICALmedium confidence
EG Risk
65
EG Risk 65/100CISA 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
Severity98% × 45%
Exploitation40% × 40%
Automatability30% × 15%
CISA SSVC: Track at low, Track* at medium and Attend at high mission impact.
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.
EPSS PROB
3.9%
EPSS %ILE
89th
KEV
Not listed

CISA SSVCTrack at low, Track* at medium and Attend at high mission impact.

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.

Exploitation public PoC (EG-KEV: elevated) · Automatable unknown (not published for this CVE) · Technical impact total (CVSS ≥ 9.0). 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 15, 2026

Last Modified

August 20, 2026

References (9)

Vendor Advisories for CVE-2026-15826(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 33× in last 7d / 185× 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 356 total refreshes for this CVE.

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

Publicly available exploits

(1 reference)

Working exploit code is in the public domain. Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • Nucleihttp/cves/2026/CVE-2026-15826.yaml
    First seen Jan 1, 2026

    User Profile Builder 3.16.4 - Unauthenticated Authentication Bypass

    Open source ↗

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-15826?
CVE-2026-15826 is a critical vulnerability published on August 15, 2026. The User Profile Builder plugin for WordPress is vulnerable to Authentication Bypass via Type Confusion in versions up to, and including, 3.16.4. This is due to the wppbloginuser() function calling absint() on the return value of wpinsertuser() before performing an iswperror() check — when a…
When was CVE-2026-15826 disclosed?
CVE-2026-15826 was first published on August 15, 2026, with the most recent update on August 20, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-15826 actively exploited?
CVE-2026-15826 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 3.9% probability of exploitation in the next 30 days (89th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-15826?
CVE-2026-15826 has a CVSS base score of 9.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-15826?
No fix for CVE-2026-15826 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-15826 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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