[NEW] [high] Dovecot: Multiple vulnerabilities
An attacker can exploit multiple vulnerabilities in Dovecot to bypass security measures, disclose sensitive information, manipulate data, or cause denial-of-service conditions.
CSIRTS triage
- What
- Dovecot contains multiple vulnerabilities allowing attackers to bypass security measures, disclose sensitive information, manipulate data, or cause denial-of-service.
- Who is affected
- All Dovecot mail server deployments running affected versions.
- Urgency
- High; multiple unpatched vulnerabilities affecting a critical email infrastructure component.
- Action
- Update Dovecot to the latest version addressing CVE-2023-51764, CVE-2023-51766, and CVE-2026-27852 through CVE-2026-33607.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2026-3076
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Moderate exploitation riskCVE-2023-517642.6% 30-day exploitation probability. Patch within normal cadence, watch for KEV listing. Riskier than 84% of all EPSS-scored CVEs.
- Moderate exploitation riskCVE-2023-517661.1% 30-day exploitation probability. Patch within normal cadence, watch for KEV listing. Riskier than 63% of all EPSS-scored CVEs.
Referenced CVEs
Same CVEs, other sources
How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.
- unknownGitHub Enterprise Server Multiple Vulnerabilitieshkcert
- mediumCVE-2026-73209: An attacker that has valid credentials can send crafted compressed data that causes the affect…nvd
- highCVE-2026-73208: An attacker that holds a token intended for a different purpose can authenticate, because when…nvd
- mediumCVE-2026-52687: An attacker that has valid credentials can select a compression algorithm for the IMAP connect…nvd
- lowCVE-2026-52681: Sieve CPU resource usage is tracked in the compiled script, so an attacker that has valid cred…nvd
- mediumCVE-2026-42395: A host listed as a trusted proxy can send forwarding information containing a NUL byte, which …nvd
- lowCVE-2026-42393: The comparison used for the doveadm password and API key is not fully timing safe and can reve…nvd
- mediumCVE-2026-42392: An attacker that has valid credentials can send an invalid IMAP URLFETCH command, which causes…nvd
- highCVE-2026-42391: An unauthenticated attacker can send an IMAP ID command with a very large number of parameters…nvd
- mediumCVE-2026-42008: Forwarding information received from a host listed as a trusted proxy is not kept separate fro…nvd
- criticalCVE-2026-42007: An attacker that has valid credentials can use a Sieve script with the editheader extension to…nvd
- mediumCVE-2026-40205: An attacker that holds an OAuth2 token granting only part of the required scopes can authentic…nvd
Recent advisories for Dovecot
A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.
- mediumCVE-2026-42008: Forwarding information received from a host listed as a trusted proxy is not kept separate fro…nvd · 2026-08-28
- mediumCVE-2026-33604: An attacker that can get Dovecot to relay a message, for example through Sieve redirect or sub…nvd · 2026-08-28
- medium[UPDATE] [medium] OX Dovecot Pro: Multiple Vulnerabilitiescert-bund · 2026-08-11
- medium[UPDATE] [medium] Dovecot: Multiple vulnerabilitiescert-bund · 2026-08-11
- medium[UPDATE] [medium] Dovecot: Multiple vulnerabilities enable Denial of Servicecert-bund · 2026-08-11
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