Cyrus IMAP up to 3.8.7/3.10.3/3.12.3 CalDAV double free

CVSS Meta Temp Score
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CTI Interest Score
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5.1$0-$5k0.00

Summaryinfo

A vulnerability was found in Cyrus IMAP up to 3.8.7/3.10.3/3.12.3. It has been classified as problematic. Affected by this issue is some unknown functionality of the component CalDAV. This manipulation causes double free. This vulnerability is registered as CVE-2026-61915. Remote exploitation of the attack is possible. No exploit is available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Cyrus IMAP up to 3.8.7/3.10.3/3.12.3. It has been declared as problematic. Affected by this vulnerability is an unknown code block of the component CalDAV. The manipulation with an unknown input leads to a double free vulnerability. The CWE definition for the vulnerability is CWE-415. The product calls free() twice on the same memory address, potentially leading to modification of unexpected memory locations. As an impact it is known to affect availability. The summary by CVE is:

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.

This vulnerability is known as CVE-2026-61915 since 07/13/2026. The exploitation appears to be easy. The attack can be launched remotely. The technical details are unknown and an exploit is not publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 352197 (CentOS Linux 8.4 [TuxCare] Security Update: cyrus-imapd / cyrus-imapd-devel / cyrus-imapd-doc-extra / etc (CENTOS8.4:CLSA-2026:1790758129)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 3.8.8, 3.10.4 or 3.12.4 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (352197). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.2
VulDB Meta Temp Score: 5.1

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 7.1
NVD Vector: 🔒

CNA Base Score: 4.2
CNA Vector (MITRE): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Double free
CWE: CWE-415 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 352197
Nessus Name: CentOS Linux 8.4 [TuxCare] Security Update: cyrus-imapd / cyrus-imapd-devel / cyrus-imapd-doc-extra / etc (CENTOS8.4:CLSA-2026:1790758129)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Cyrus IMAP 3.8.8/3.10.4/3.12.4

Timelineinfo

07/13/2026 CVE reserved
09/09/2026 +58 days Advisory disclosed
09/09/2026 +0 days VulDB entry created
10/01/2026 +22 days VulDB entry last update

Sourcesinfo

Status: Confirmed

CNA: MITRE
CVE: CVE-2026-61915 (🔒)

GCVE (CVE): GCVE-0-2026-61915
GCVE (VulDB): GCVE-100-401875

Entryinfo

Created: 09/09/2026 22:26
Updated: 10/01/2026 06:12
Changes: 09/09/2026 22:26 (61), 09/18/2026 11:39 (11), 10/01/2026 06:12 (2)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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