Cyber Resilience

CVE-2026-43879

Medium

Published: 11 May 2026

Published
11 May 2026
Modified
15 May 2026
KEV Added
Patch
CVSS Score v3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
EPSS Score 0.0016 6.0th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-43879 is a medium-severity SSRF (CWE-918) vulnerability. Its CVSS base score is 5.4 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 6.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability details

WWBN AVideo is an open source video platform. In versions up to and including 29.0, an authenticated user can configure their own donation-notification webhook URL to point at internal/loopback/metadata hosts (e.g. http://127.0.0.1:8080/..., http://169.254.169.254/latest/..., RFC1918 addresses). When any other user (including…

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a second account owned by the same attacker) donates even a trivial amount via plugin/CustomizeUser/donate.json.php, the AVideo server issues a curl POST to the attacker-supplied URL, resulting in a blind SSRF. The handler uses only isValidURL() (which is a format check) and does not call the codebase's own isSSRFSafeURL() helper. Additionally, CURLOPT_FOLLOWLOCATION is enabled with no per-hop revalidation, so even if the stored URL were validated, an HTTP 307 from an attacker-controlled host could redirect the POST to internal targets. Commit aaacd48f29f1ff71d1eb5fc81d37605f593cefa9 contains an updated fix.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1552.005 Cloud Instance Metadata API Credential Access
Adversaries may attempt to access the Cloud Instance Metadata API to collect credentials and other sensitive data.
Why these techniques?

SSRF in public-facing app directly enables T1190; explicit support for 169.254.169.254 and internal RFC1918 targets enables cloud metadata access (T1522/T1552.005).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

Affected Assets

In
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-918

Penetration testing attempts server-side requests to internal resources, identifying SSRF weaknesses for remediation.

addresses: CWE-918

Outbound connections to external resources can be monitored and limited at the boundary, reducing SSRF impact.

addresses: CWE-918

Validates server-side URLs and resource references to block SSRF attempts.

addresses: CWE-918

Detects server-side request forgery through monitoring of unexpected outbound connections.

References