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CVE-2026-61915VulnerabilityPublished 09/09/2026Updated 09/10/2026

CVE-2026-61915: CWE-415 Double Free in cyrusimap Cyrus IMAP

Affects cyrusimap Cyrus IMAPSource CVE Database V5

0

Not known to be exploited · CVSS 4.2 Medium.

Data as of 10/25/2026, 04:40:13 UTC

CVSS 3.1 base score
4.2Medium
How severe the flaw is on the 0–10 CVSS scale.
Exploitation

Not in CISA KEV, no exploitation reported

EPSS
0.2% chance of exploitation in 30 days – higher than 16% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:L

What to do

Affected software

ProductAffectedFixed in
cyrusimapCyrus IMAPAffected
  • <3.8.8
  • >=3.9.0 <3.10.4
  • >=3.11.0 <3.12.4
Fixed in
  • 3.8.8
  • 3.10.4
  • 3.12.4

AI-suggested

No explicit patch or remediation is provided in the input data. Until a fix is available, restrict authenticated user privileges and monitor for unusual PATCH request activity targeting calendar resources.

Description

CVE-2026-61915 is a medium severity double-free vulnerability in Cyrus IMAP before version 3.12.4. It occurs when an authenticated calendar user sends a PATCH request with a specific PATCH-ACTION parameter to a resource containing multiple properties of the same kind, causing the Cyrus CalDAV worker to crash due to memory being freed multiple times.

Impact

An authenticated calendar user can cause a denial of service by crashing the Cyrus CalDAV worker through a crafted PATCH request. There is no indication of confidentiality or significant integrity impact. The primary impact is availability disruption due to the crash.

Weaknesses

References

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