CVE-2026-40015

MEDIUMCVSS 4.3/10EPSS 0.29%

Last modified

CVE-2026-40015 is a medium-severity vulnerability rated 4.3/10 on the CVSS scale. An attacker that has valid credentials can open many connections to the imap-hibernate service and send invalid commands, which can intermittently cause an out-of-bounds read and crash the process. The crash interrupts hibernated IMAP sessions handled by the affected process, which can cause degradation of service for IMAP. EPSS estimates a 0.29% chance of exploitation in the next 30 days.

Description

An attacker that has valid credentials can open many connections to the imap-hibernate service and send invalid commands, which can intermittently cause an out-of-bounds read and crash the process. The crash interrupts hibernated IMAP sessions handled by the affected process, which can cause degradation of service for IMAP. Disable IMAP hibernation. Update to non-vulnerable version. No publicly available exploits are known.

Metrics

EPSS Probability
0.29%

21.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
Open-Xchange GmbHOX Dovecot Pro>= 2.3.0, < 2.3.22.2; >= 3.0.0, < 3.0.7; >= 3.1.0, < 3.1.6
Open-Xchange GmbHOX Dovecot CE>= 2.3.0, < 2.4.5

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is CVE-2026-40015?
An attacker that has valid credentials can open many connections to the imap-hibernate service and send invalid commands, which can intermittently cause an out-of-bounds read and crash the process. The crash interrupts hibernated IMAP sessions handled by the affected process, which can cause degradation of service for IMAP. Disable IMAP hibernation. Update to non-vulnerable version. No publicly available exploits are known.
How severe is CVE-2026-40015?
CVE-2026-40015 has a CVSS score of 4.3/10 (MEDIUM severity). The EPSS model estimates a 0.29% probability of exploitation in the next 30 days.
How do I fix CVE-2026-40015?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST