CVE-2026-40013
published 2026-08-28CVE-2026-40013: An attacker that has valid credentials can submit a Sieve script containing an extreme numeric literal, which causes an out-of-bounds write when the…
PriorityP429medium4.3CVSS 3.1
AVNACLPRLUINSUCNINAL
EPSS
0.87%
58.3th percentile
An attacker that has valid credentials can submit a Sieve script containing an extreme numeric literal, which causes an out-of-bounds write when the ManageSieve service compiles the script. This causes memory corruption and an observed crash of the ManageSieve process, resulting in denial of service for script management. This might be able to be used for remote code execution. Disable the ManageSieve service if users do not need remote Sieve script management. Update to non-vulnerable version. No publicly available exploits are known.
Affected
5 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| dovecot | dovecot | — | — |
| open-xchange_gmbh | ox_dovecot_ce | >= 2.3.0 < 2.4.5 | 2.4.5 |
| open-xchange_gmbh | ox_dovecot_pro | >= 2.3.0 < 2.3.22.2 | 2.3.22.2 |
| open-xchange_gmbh | ox_dovecot_pro | >= 3.0.0 < 3.0.7 | 3.0.7 |
| open-xchange_gmbh | ox_dovecot_pro | >= 3.1.0 < 3.1.6 | 3.1.6 |
CVSS provenance
nvdv3.14.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
vendor_redhat4.3MEDIUM
Stop checking back — get the weekly exploitation signal.
Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.
Red Hat
dovecot: Dovecot: Denial of Service in ManageSieve service via crafted Sieve script
vendor_redhat·2026-08-28·CVSS 4.3
CVE-2026-40013 [MEDIUM] CWE-787 dovecot: Dovecot: Denial of Service in ManageSieve service via crafted Sieve script
dovecot: Dovecot: Denial of Service in ManageSieve service via crafted Sieve script
An attacker that has valid credentials can submit a Sieve script containing an extreme numeric literal, which causes an out-of-bounds write when the ManageSieve service compiles the script. This causes memory corruption and an observed crash of the ManageSieve process, resulting in denial of service for script management. This might be able to be used for remote code execution. Disable the ManageSieve service if users do not need remote Sieve script management. Update to non-vulnerable version. No publicly available exploits are known.
A flaw was found in Dovecot. An authenticated attacker can submit a specially crafted Sieve script containing an extreme numeric literal to the ManageSieve service. This ac
GHSA
An attacker that has valid credentials can submit a Sieve script containing an extreme numeric literal, which causes an out-of-bounds write when the ManageSieve service compiles the script.
ghsa_unreviewed·2026-08-28
CVE-2026-40013 [MEDIUM] CWE-124 An attacker that has valid credentials can submit a Sieve script containing an extreme numeric literal, which causes an out-of-bounds write when the ManageSieve service compiles the script.
An attacker that has valid credentials can submit a Sieve script containing an extreme numeric literal, which causes an out-of-bounds write when the ManageSieve service compiles the script. This causes memory corruption and an observed crash of the ManageSieve process, resulting in denial of service for script management. This might be able to be used for remote code execution. Disable the ManageSieve service if users do not need remote Sieve script management. Update to non-vulnerable version. No publicly available exploits are known.
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-40013 dovecot: Dovecot: Denial of Service in ManageSieve service via crafted Sieve script [fedora-all]
bugzilla·2026-09-01·CVSS 4.3
CVE-2026-40013 [MEDIUM] CVE-2026-40013 dovecot: Dovecot: Denial of Service in ManageSieve service via crafted Sieve script [fedora-all]
CVE-2026-40013 dovecot: Dovecot: Denial of Service in ManageSieve service via crafted Sieve script [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
An attacker that has valid credentials can submit a Sieve script containing an extreme numeric literal, which causes an out-of-bounds write when the ManageSieve service compiles the script. This causes memory corruption and an observed crash of the ManageSieve process, resulting in denial of service for script management. This might be able to be used for remote code execution. Disable the ManageSieve service if users do not need remote Sieve script manageme
Bugzilla
CVE-2026-40013 dovecot: Dovecot: Denial of Service in ManageSieve service via crafted Sieve script
bugzilla·2026-08-28·CVSS 4.3
CVE-2026-40013 [MEDIUM] CVE-2026-40013 dovecot: Dovecot: Denial of Service in ManageSieve service via crafted Sieve script
CVE-2026-40013 dovecot: Dovecot: Denial of Service in ManageSieve service via crafted Sieve script
An attacker that has valid credentials can submit a Sieve script containing an extreme numeric literal, which causes an out-of-bounds write when the ManageSieve service compiles the script. This causes memory corruption and an observed crash of the ManageSieve process, resulting in denial of service for script management. This might be able to be used for remote code execution. Disable the ManageSieve service if users do not need remote Sieve script management. Update to non-vulnerable version. No publicly available exploits are known.
2026-08-28
Published