CVE-2026-42006An attacker can cause uncontrolled memory usage with excessive bracing over IMAP.
Updated under an hour ago ()
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It affects Open-Xchange GmbH OX Dovecot Pro and 10 other products. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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An attacker can cause uncontrolled memory usage with excessive bracing over IMAP. The fix in CVE-2026-27857 was incomplete, only blocking one way of doing this, so there was still another way left open. In particular, the fix was for closing braces, but you could still use open braces to bypass the limit. Using excessive bracing, attacker can cause memory usage up to configured memory limit. Install fixed version, or configure vsz_limit for imap process to low value. No publicly available exploits are known.
- CVSS
- 4.3 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
- Weakness (CWE)
- CWE-400, CWE-770
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- OX
- NVD analysis
- Modified
- Record last updated
- Aug 3, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Open-Xchange GmbH OX Dovecot Pro open_xchange:ox_dovecot_pro (from the name) | through 3.0.5; through 3.1.4; through 2.4.3 | CNA record |
Red Hat Red Hat Enterprise Linux 10 redhat:enterprise_linux | from 1:2.3.21-19.el10_2.1 not affected | CISA ADP |
Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support redhat:enterprise_linux_eus | from 1:2.3.21-16.el10_0.2 not affected | CISA ADP |
from 1:2.2.36-8.el7_9.2 not affected | CISA ADP | |
from 1:2.3.8-9.el8_4.2 not affected | CISA ADP | |
Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On redhat:rhel_eus_long_life | from 1:2.3.8-9.el8_4.2 not affected | CISA ADP |
from 1:2.3.16-3.el8_8.2 not affected | CISA ADP | |
from 1:2.3.16-3.el8_8.2 not affected | CISA ADP | |
Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support redhat:rhel_eus | from 1:2.3.16-15.el9_6.2 not affected | CISA ADP |
dovecot dovecot dovecot:dovecot | before 2.4.4 | NVD |
open-xchange dovecot open-xchange:dovecot | before 3.1.5 | NVD |
References
- https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0002.jsonvendor-advisory, issue-tracking
- https://access.redhat.com/errata/RHSA-2026:41905
- https://access.redhat.com/errata/RHSA-2026:41988
- https://access.redhat.com/errata/RHSA-2026:42091
- https://access.redhat.com/errata/RHSA-2026:44355
- https://access.redhat.com/errata/RHSA-2026:44357
- https://access.redhat.com/errata/RHSA-2026:44373
- https://access.redhat.com/errata/RHSA-2026:46379
- https://access.redhat.com/errata/RHSA-2026:46380
- https://access.redhat.com/errata/RHSA-2026:46381
- https://access.redhat.com/errata/RHSA-2026:46532
- https://access.redhat.com/errata/RHSA-2026:49513
- https://access.redhat.com/security/cve/CVE-2026-42006
- https://bugzilla.redhat.com/show_bug.cgi?id=2476476
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42006.json
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.