CVE-2026-61909 (CVSS 3.5)

Description

An issue was discovered in Cyrus IMAP before 3.12.4. CalDAV/CardDAV multiget bypasses a per-href ACL. An authenticated DAV user with some shared access to another user's calendar or address book could read even unshared events or contacts by including the target hrefs in a calendar-multiget or addressbook-multiget REPORT.

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CVSS v3.1 Score

3.5

LOW

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

EPSS — Exploit Prediction

0.0020

Probability of exploitation

0.11%

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-420 CWE-420

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-2026-61909? +

An issue was discovered in Cyrus IMAP before 3.12.4. CalDAV/CardDAV multiget bypasses a per-href ACL. An authenticated DAV user with some shared access to another user's calendar or address book could read even unshared events or contacts by including the target hrefs in a calendar-multiget or addressbook-multiget REPORT. It has a CVSS v3.1 base score of 3.5 (LOW).

How severe is CVE-2026-61909? +

CVE-2026-61909 has a CVSS v3.1 score of 3.5 out of 10, rated LOW. This is a low-severity vulnerability with limited impact. The EPSS score is 0.0020, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-61909? +

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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CVE-2026-61909