CVE-2026-33603Attacker can use a specially crafted base64 exchange between Dovecot and Client to fake SCRAM TLS channel binding.
Updated under an hour ago ()
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It affects dovecot and 1 other product. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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Attacker can use a specially crafted base64 exchange between Dovecot and Client to fake SCRAM TLS channel binding. This requires that the attacker is able to position itself between Dovecot and the client connection. If successful, the attacker can eavesdrop communications between Dovecot and client as MITM proxy. Install fixed version. No publicly available exploits are known.
- CVSS
- 5.3 MEDIUM (v3.1, NVD)CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
- Weakness (CWE)
- CWE-99
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Not given
- NVD analysis
- Analyzed
- Record last updated
- Jun 17, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
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
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.