HOMEVULNERABILITIESCVE-2026-27851
CRITICAL

CVE-2026-27851

CWE-235Published: May 12, 2026· Updated: May 18, 2026

9.1
CVSS v3.1
EPSS:0.01%probability of exploitation in 30 daysPercentile:1.8th

Official Description

When safe filter is used with variable expansion, all following pipelines on the same string are incorrectly interpreted as safe too, enabling unsafe data to be unescaped. This can enable SQL / LDAP injection attacks when used in authentication. Avoid using safe filter until on fixed version. No publicly available exploits are known.

NVD Source

Technical Analysis

CVE-2026-27851 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), with a CVSS base score of 9.1.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected Vendors & Products

dovecot1 product
dovecot
open-xchange1 product
dovecot
Source: NVD CPE · 2 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0002.json

All References (1)

→
https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0002.jsonVendor Advisory

Quick Facts

CVE IDCVE-2026-27851
CVSS Score9.1 / 10
SeverityCRITICAL
WeaknessCWE-235
CISA KEVNo
EPSS (30d)0.01%
Affected2 vendors
PublishedMay 12, 2026

Related CVEs (CWE-235)

CVE-2026-20083
6.5

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2026-27851 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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