CVE-2026-61915: Double Free (CVSS 4.2)

Description

An issue was discovered in Cyrus IMAP before 3.12.4. There is a VPATCH BYPARAM double-free. An authenticated calendar user could crash a Cyrus CalDAV worker with a PATCH containing PATCH-ACTION="BYPARAM@..." against a resource with two or more properties of the matched kind. The memory holding the selector would be freed once on each iteration over the properties.

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CVSS v3.1 Score

4.2

MEDIUM

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

EPSS — Exploit Prediction

0.0022

Probability of exploitation

0.12%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-415 CWE-415

References

Other References

https://cyrusimap.org https://www.cyrusimap.org/3.12/imap/download/release-notes/3.10/x/3.10.4.html https://www.cyrusimap.org/3.12/imap/download/release-notes/3.12/x/3.12.4.html https://www.cyrusimap.org/3.12/imap/download/release-notes/3.8/x/3.8.8.html

Frequently Asked Questions

What is CVE-2026-61915? +

An issue was discovered in Cyrus IMAP before 3.12.4. There is a VPATCH BYPARAM double-free. An authenticated calendar user could crash a Cyrus CalDAV worker with a PATCH containing PATCH-ACTION="BYPARAM@..." against a resource with two or more properties of the matched kind. The memory holding the selector would be freed once on each iteration over the properties. It has a CVSS v3.1 base score of 4.2 (MEDIUM).

How severe is CVE-2026-61915? +

CVE-2026-61915 has a CVSS v3.1 score of 4.2 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0022, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-61915? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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