CVE-2026-2559

MEDIUMNVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

Score 5.3 from GitHub Security Advisory published 2026-03-18. NVD baseline CVSS 5.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
5.3
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.3Exploit: NoneExposed: 0

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

The Post SMTP plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the handle_office365_oauth_redirect() function in all versions up to, and including, 3.8.0. This is due to the function being hooked to admin_init without any current_user_can() check or nonce verification. This makes it possible for authenticated attackers, with Subscriber-level access and above, to overwrite the site's Office 365 OAuth mail configuration (access token, refresh token, and user email) via a crafted URL. The configuration option is used during wizard setup of Microsoft365 SMTP, only available in the Pro option of the plugin. This could cause an Administrator to believe an attacker-controlled Azure app is their own, and lead them to connect the plugin to the attacker's account during configuration after upgrading to Pro.

CVSS v3
5.3
EG Score
5.3(medium)
EPSS
12.5%
KEV
Not listed

Published

March 18, 2026

Last Modified

April 22, 2026

References (4)

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 13× in last 7d / 45× 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 114 total refreshes for this CVE.

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-2559?
CVE-2026-2559 is a medium vulnerability published on March 18, 2026. The Post SMTP plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the handleoffice365oauthredirect() function in all versions up to, and including, 3.8.0. This is due to the function being hooked to admininit without any currentusercan()…
When was CVE-2026-2559 disclosed?
CVE-2026-2559 was first published in the National Vulnerability Database on March 18, 2026, with the most recent update on April 22, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-2559 actively exploited?
CVE-2026-2559 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 12.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-2559?
CVE-2026-2559 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-2559?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-2559, 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.

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