CVE-2026-115479 baserproject CVE debrief

Who should care

Defenders responsible for baserCMS installations, particularly those using versions 5.2.5 to 5.3.2 and 5.4.0 to 5.4.2, should assess exposure and prioritize patching or compensating controls.

Why it matters

CVE-2026-115479 allows unauthenticated visitors to supply a comma-separated address list in a public mail form's email field, causing a single auto-reply to be addressed to multiple third parties. Defenders should prioritize verifying exposure, assessing potential abuse, and applying patches or compensating controls.

• Potential for abuse of the site to deliver unsolicited mail
• Possible exposure of mail forms to unauthorized parties
• Need for verification of affected versions and patch application
• Potential impact on site reputation due to unsolicited mail

Technical summary

The vulnerability exists in the mail form functionality of baserCMS, allowing an unauthenticated visitor to supply a comma-separated address list in the email field. This causes a single auto-reply to be addressed to multiple third parties. The issue has been patched in versions 5.3.2 and 5.4.2. Defenders should prioritize verifying exposure of mail forms using the vulnerable baserCMS versions and assess the potential for abuse of the site to deliver unsolicited mail. The vulnerability enables attackers to potentially abuse the site for delivering unsolicited mail, impacting site reputation and mail form security.

Defensive priority

Defenders should prioritize verifying exposure of mail forms using the vulnerable baserCMS versions and assess the potential for abuse of the site to deliver unsolicited mail.

Recommended defensive actions

• Verify the exposure of mail forms using baserCMS versions 5.2.5 to 5.3.2 and 5.4.0 to 5.4.2
• Assess the potential for abuse of the site to deliver unsolicited mail
• Apply patches to affected versions (5.3.2 and 5.4.2) or implement compensating controls
• Monitor for suspicious mail activity
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record and source item provide details on the vulnerability, including the affected versions and the patch releases. However, there is limited information on actual exploitation or victim impact.

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.