CVE-2026-43876

MEDIUMNVD 6.46.4—
EchelonGraph scoreMEDIUM confidence

Score 6.4 from GitHub Security Advisory published 2026-05-05. NVD baseline CVSS 6.4; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Elevated
6.4EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.4Exploit: Elevated riskExposed: 0

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

WWBN AVideo is an open source video platform. In versions up to and including 29.0, objects/notifySubscribers.json.php takes the raw message POST parameter and passes it into sendSiteEmail(), which substitutes it directly into an HTML email template (via str_replace on the {message} placeholder) and renders it with PHPMailer::msgHTML(). There is no HTML sanitization, character escaping, or output encoding on the attacker-controlled message between $_POST['message'] and the rendered email. Any authenticated user with upload permission can therefore broadcast arbitrary HTML — phishing links, tracking pixels, CSS/UI spoofing — to every subscriber on their channel (up to 10,000 recipients per invocation). The email is sent From: the platform's configured contact address and wrapped in the site's official logo and title, so attacker-supplied HTML arrives with the appearance of an official platform communication. Commit https://github.com/WWBN/AVideo/commit/ contains an updated fix.

CVSS v3
6.4
EG Score
6.4(medium)
EG Risk
45(Track)
EG Risk 45/100SSVC: 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
Severity64% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
5%
KEV
Not listed

Published

May 11, 2026

Last Modified

May 13, 2026

Advisory Details (2)

Auto-updated May 11, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

HTML Injection in notifySubscribers.json.php Enables Platform-Branded Phishing Emails to Channel Subscribers · Advisory · WWBN/AVideo · GitHub

https://github.com/WWBN/AVideo/security/advisories/GHSA-g9cm-rxp7-6gv5
generic

feat: Ensure message is sanitized and converted to plain text before … · WWBN/AVideo@078c434 · GitHub

https://github.com/WWBN/AVideo/commit/078c4342eb9969a70425a9cdca3eefa7f8a86d53

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
composerwwbn/avideo—ghsa

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.

Affected Packages

(1 across 1 ecosystem)
Packagist(1)
PackageVulnerable rangeFixed inDependents
wwbn/avideo10.4 ... 29.0 (18 versions)——

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 29× 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 179 total refreshes for this CVE.

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

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-43876?
CVE-2026-43876 is a medium vulnerability published on May 11, 2026. WWBN AVideo is an open source video platform. In versions up to and including 29.0, objects/notifySubscribers.json.php takes the raw message POST parameter and passes it into sendSiteEmail(), which substitutes it directly into an HTML email template (via strreplace on the {message} placeholder) and…
When was CVE-2026-43876 disclosed?
CVE-2026-43876 was first published in the National Vulnerability Database on May 11, 2026, with the most recent update on May 13, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-43876 actively exploited?
CVE-2026-43876 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 94.9% of all scored CVEs.
What is the CVSS score of CVE-2026-43876?
CVE-2026-43876 has a CVSS v3 base score of 6.4 (NVD).
How do I remediate CVE-2026-43876?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-43876, 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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