VulnerabilityPublished 11 May 2026

CVE-2026-43880: WWBN AVideo · Improper Verification of Source of a Communication Channel

Affects WWBN AVideoSource CVE Database V5

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Not known to be exploited · CVSS 5.3 Medium.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 21% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 11 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
WWBNAVideo	Affected <=29.0	Fixed in–
GitHubwwbn/AVideo`pkg:github/wwbn/AVideo`Other threats	Affected <=29.0	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Until an official fix is released, consider restricting access to the vulnerable endpoint or implementing additional verification controls to prevent unauthenticated abuse. Monitor vendor channels for updates and apply the official fix once available.

Description

CVE-2026-43880 is a medium severity vulnerability in WWBN AVideo versions up to and including 29.0. The vulnerability exists in the objects/sendEmail.json.php endpoint, which allows unauthenticated attackers to send emails using the site's legitimate SMTP infrastructure. This endpoint is explicitly allow-listed as a public write action and requires no authentication or CSRF token. An attacker who solves a captcha can supply arbitrary recipient email addresses and cause the site to send emails that appear to come from the site's own domain, passing SPF, DKIM, and DMARC checks. This can facilitate targeted phishing and brand impersonation attacks. A fix has been committed but no official patch or vendor advisory is currently provided.

Impact

The vulnerability allows unauthenticated attackers to send emails from the affected server's legitimate SMTP infrastructure using the site's own domain in the From/Reply-To fields. This can be exploited to conduct targeted phishing campaigns and brand impersonation attacks that are more likely to bypass email authentication controls (SPF, DKIM, DMARC). There is no direct impact on confidentiality or availability reported. No known exploits in the wild have been documented at this time.

Summary

WWBN AVideo versions up to 29.0 contain an improper verification of the source of a communication channel (CWE-940) in the sendEmail.json.php endpoint. When the contactForm parameter is omitted, the endpoint sets the recipient email address ($sendTo) to an attacker-controlled value and uses the site's own contact email as the From/Reply-To address. This endpoint is allow-listed as a public write action without requiring authentication or CSRF protection. Consequently, an unauthenticated attacker who can solve a captcha can abuse the site's SMTP infrastructure to send arbitrary emails that appear to originate legitimately from the site's domain, potentially bypassing email authentication mechanisms such as SPF, DKIM, and DMARC. This vulnerability enables phishing and brand impersonation attacks.

CWE-940Improper Verification of Source of a Communication Channel (opens in a new tab)
Base weaknessOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
The product establishes a communication channel to handle an incoming request that has been initiated by an actor, but it does not properly verify that the request is coming from the expected origin.
Architecture and Design
Use a mechanism that can validate the identity of the source, such as a certificate, and validate the integrity of data to ensure that it cannot be modified in transit using an Adversary-in-the-Middle (AITM) attack.
OWASP Cheat Sheets
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V1.14.1 (opens in a new tab)
V14.5.2 (opens in a new tab)
V14.5.3 (opens in a new tab)
Attack patterns
WebView Injection (opens in a new tab)
Connection Reset (opens in a new tab)
TCP RST Injection (opens in a new tab)
Traffic Injection (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 19 May 2026, 11:05 UTC

WeaknessesCWE-940

Technical details

References

Community reviews

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