CVE-2026-39498 Yeeaddons CVE debrief

Who should care

Defenders responsible for managing and securing YayMail installations should assess exposure and prioritize patching or mitigation efforts.

Why it matters

CVE-2026-39498 is a PHP Object Injection vulnerability in YayMail that requires verification of exposure and potential patching or mitigation efforts to prevent exploitation.

• Potential for code execution with high privileges
• Possible data breaches or unauthorized access
• Required verification of YayMail version and exposure

Technical summary

The CVE-2026-39498 vulnerability is a PHP Object Injection issue in YayMail versions up to 4.3.3. The vulnerability has a CVSS score of 7.2 and is considered HIGH severity. The CVSS vector is CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.

Defensive priority

Defenders should prioritize verifying exposure and applying patches or mitigations, if available, to prevent potential exploitation.

Recommended defensive actions

• Verify YayMail version and check for updates to 4.3.4 or later
• Restrict access to sensitive areas of the application
• Monitor for suspicious activity

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, including its CVSS score and severity. However, additional information on exploitation or impact is not provided in the source corpus.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.