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
Trending — 3 sources updated this weekElevated
6.4
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.4Exploit: NoneExposed: 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
5.2%
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 9× in last 7d / 35× 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.

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

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 5.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
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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