{"cve":"CVE-2026-27857","nvd":{"published":"2026-03-27T09:16:19.917","modified":"2026-10-26T22:10:00.163","status":"Modified","description":"Sending \"NOOP (((...)))\" command with 4000 parenthesis open+close results in ~1MB extra memory usage. Longer commands will result in client disconnection. This 1 MB can be left allocated for longer time periods by not sending the command ending LF. So attacker could connect possibly from even a single IP and create 1000 connections to allocate 1 GB of memory, which would likely result in reaching VSZ limit and killing the process and its other proxied connections. Attacker could connect possibly from even a single IP and create 1000 connections to allocate 1 GB of memory, which would likely result in reaching VSZ limit and killing the process and its other proxied connections. Install fixed version, there is no other remediation. No publicly available exploits are known.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-400","CWE-770"],"references":["https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0001.json","https://access.redhat.com/errata/RHSA-2026:13498","https://access.redhat.com/errata/RHSA-2026:13830","https://access.redhat.com/errata/RHSA-2026:13857","https://access.redhat.com/errata/RHSA-2026:17602"],"products":["dovecot:dovecot","open-xchange:dovecot"],"source":"nvd","synced_at":"2026-10-26T22:26:44.656832877+00:00"},"epss":{"cve":"CVE-2026-27857","score":0.00679,"percentile":0.52097,"date":"2026-10-26"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}