CVE-2026-27858

Attacker can send a specifically crafted message before authentication that causes managesieve to allocate large amount of memory. Attacker can force managesieve-login to be unavailable by repeatedly crashing the process. Protect access to managesieve protocol, or install fixed version. No publicly available exploits are known.

Database specific

{
    "cwe_ids": [
        "CWE-400"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27858.json",
    "cna_assigner": "OX",
    "unresolved_ranges": [
        {
            "extracted_events": [
                {
                    "last_affected": "2.3.0"
                },
                {
                    "last_affected": "3.1.0"
                },
                {
                    "last_affected": "2.4.0"
                }
            ],
            "source": "AFFECTED_FIELD"
        }
    ]
}

References

Affected packages

Git / github.com/dovecot/core

Affected ranges

Type

GIT

Repo

https://github.com/dovecot/core

Events

Introduced

Fixed

c1b22ef978ca72999e254b2f3964b3d32d1a4979

Database specific

Show details

{
    "cpe": "cpe:2.3:a:dovecot:dovecot:*:*:*:*:*:*:*:*",
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "2.4.3"
        }
    ],
    "source": "CPE_RANGE"
}

Affected versions

1.*

1.1.alpha1

1.1.alpha2

1.1.alpha4

1.1.alpha5

1.1.alpha6

1.1.beta1

1.1.beta10

1.1.beta11

1.1.beta12

1.1.beta13

1.1.beta14

1.1.beta16

1.1.beta2

1.1.beta3

1.1.beta4

1.1.beta5

1.1.beta6

1.1.beta8

1.1.beta9

1.1.rc1

1.1.rc2

1.1.rc3

1.2.alpha1

1.2.alpha2

1.2.alpha3

1.2.alpha4

1.2.alpha5

1.2.beta1

1.2.beta2

1.2.beta3

1.2.beta4

1.2.rc1

2.*

2.0.0

2.0.1

2.0.2

2.0.3

2.0.4

2.0.5

2.0.6

2.0.7

2.0.8

2.0.alpha1

2.0.alpha2

2.0.alpha3

2.0.beta1

2.0.beta2

2.0.beta3

2.0.beta4

2.0.beta5

2.0.beta6

2.0.rc1

2.0.rc2

2.0.rc3

2.0.rc4

2.0.rc5

2.0.rc6

2.1.alpha1

2.1.alpha2

2.1.beta1

2.1.rc1

2.1.rc2

2.1.rc3

2.1.rc4

2.1.rc5

2.1.rc6

2.2.0

2.2.1

2.2.10

2.2.11

2.2.12

2.2.13

2.2.13.rc1

2.2.14

2.2.14.rc1

2.2.15

2.2.16

2.2.16.rc1

2.2.17

2.2.17.rc1

2.2.17.rc2

2.2.18

2.2.19

2.2.19.rc1

2.2.19.rc2

2.2.2

2.2.20

2.2.20.rc1

2.2.3

2.2.4

2.2.5

2.2.6

2.2.7

2.2.8

2.2.9

2.2.alpha1

2.2.beta1

2.2.beta2

2.2.rc1

2.2.rc2

2.2.rc3

2.2.rc4

2.2.rc5

2.2.rc6

2.2.rc7

Database specific

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-27858.json"