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TI-2026-51345 Aliases CVE-2026-73208GHSA-856w-5q8f-fq73

Improper authentication in Open-Xchange GmbH OX Dovecot Pro

Priority LOW 34CWE-287Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Impact type
Security bypass
Confidentiality · integrity · availability
High · High · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-287.

Summary

An attacker that holds a token intended for a different purpose can authenticate, because when an OAuth2 token response does not contain a scope claim, the audience claim is used in its place and checked against the configured required scopes. These are different concepts, and the audience claim does not describe what a token is allowed to do. A token that grants no relevant permissions can be accepted because its intended recipient value happens to match a configured scope name, granting access that should have been denied. It also hides an identity provider misconfiguration where scopes are not being issued at all. Ensure the identity provider issues a scope claim for all tokens used with Dovecot, and that configured scope names do not match audience values. Update to non-vulnerable version. No publicly available exploits are known.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00312 24th percentileScored 2026-11-07
Fix Fixed OX Dovecot Pro (Open-Xchange GmbH): 2.3.22.2, 3.0.7, 3.1.6OX Dovecot CE (Open-Xchange GmbH): 2.4.5Red Hat: 3 advisories

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
Open-Xchange GmbHOX Dovecot Pro2.3.13 to before 2.3.22.2; 3.0.0 to before 3.0.7; 3.1.0 to before 3.1.62.3.22.2, 3.0.7, 3.1.6Patch availableCNA
Open-Xchange GmbHOX Dovecot CE2.3.13 to before 2.4.52.4.5Patch availableCNA
  • OX Dovecot Pro VendorOpen-Xchange GmbH Affected 2.3.13 to before 2.3.22.2; 3.0.0 to before 3.0.7; 3.1.0 to before 3.1.6 Fixed in 2.3.22.2, 3.0.7, 3.1.6 Patch available CNA
  • OX Dovecot CE VendorOpen-Xchange GmbH Affected 2.3.13 to before 2.4.5 Fixed in 2.4.5 Patch available CNA

Remediation

  • Fix · CNA OX Dovecot Pro (Open-Xchange GmbH) Fixed in 2.3.22.2, 3.0.7, 3.1.6
  • Fix · CNA OX Dovecot CE (Open-Xchange GmbH) Fixed in 2.4.5

Red Hat 3 advisories

  • RHSA-2026:80825 Released 2026-10-12 · Red Hat rating Important
    dovecot security update
    • Red Hat Enterprise Linux AppStream (v. 9) dovecot-1:2.3.16-18.el9_8.8, dovecot-mysql-1:2.3.16-18.el9_8.8, dovecot-pgsql-1:2.3.16-18.el9_8.8 +1
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) dovecot-1:2.3.16-18.el9_8.8, dovecot-devel-1:2.3.16-18.el9_8.8
  • RHSA-2026:79371 Released 2026-10-08 · Red Hat rating Important
    dovecot security update
    • Red Hat Enterprise Linux AppStream (v. 10) dovecot-1:2.3.21-19.el10_2.8, dovecot-mysql-1:2.3.21-19.el10_2.8, dovecot-pgsql-1:2.3.21-19.el10_2.8 +1
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) dovecot-devel-1:2.3.21-19.el10_2.8
  • RHSA-2026:76763 Released 2026-10-06 · Red Hat rating Important
    dovecot security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 8) dovecot-1:2.3.16-16.el8_10, dovecot-mysql-1:2.3.16-16.el8_10, dovecot-pgsql-1:2.3.16-16.el8_10 +1
    • Red Hat Enterprise Linux CRB (v. 8) dovecot-1:2.3.16-16.el8_10, dovecot-devel-1:2.3.16-16.el8_10

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Advisory ·

    Open-Xchange OX Dovecot CE, OX Dovecot Pro — documentation.open-xchange.com/dovecot/security/advisories/…

    25 records Highest priority Priority LOW 25 LOW

    Other records, highest priority first

    • TI-2026-30691 Uncontrolled resource consumption in Open-Xchange GmbH OX Dovecot ProPriority LOW 39
    • TI-2026-30395 Use after free in Open-Xchange GmbH OX Dovecot ProPriority LOW 39
    • TI-2026-25987 Uncontrolled resource consumption in Open-Xchange GmbH OX Dovecot ProPriority LOW 39
    Show all 25 records → Advisory →

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:79371
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2026:76763
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:80825
Red Hat Enterprise Linux CRB (v. 8)Fixed RHSA-2026:76763
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:79371
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2026:80825
Not affected: 2 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-73208
  2. 2026-10-03 Alias added: GHSA-856w-5q8f-fq73
  3. 2026-10-07 Fix available: RHSA-2026:76763 · Red Hat
  4. 2026-10-07 Fix available: Red Hat Enterprise Linux AppStream (v. 8), Red Hat Enterprise Linux CRB (v. 8) · Red Hat
  5. 2026-10-09 Fix available: RHSA-2026:79371 · Red Hat
  6. 2026-10-09 Fix available: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) · Red Hat
  7. 2026-10-12 Fix available: RHSA-2026:80825 · Red Hat
  8. 2026-10-13 Fix available: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) · Red Hat

References

Advisory 1

  • TI-2024-04069 Improper check for unusual conditions in Mozilla Firefox CVSS 3.1HIGH 8.8
  • TI-2022-17394 OX App Suite through 7.10.6 allows SSRF because the anti-SSRF protection mechanism only… CVSS 3.1MEDIUM 5.3
  • TI-2022-17393 OX App Suite through 7.10.6 has Uncontrolled Resource Consumption via a large request… CVSS 3.1MEDIUM 5.3
  • TI-2022-17392 OX App Suite through 7.10.6 has Uncontrolled Resource Consumption via a large location… CVSS 3.1MEDIUM 5.3
  • TI-2022-17391 OX App Suite through 7.10.6 allows XSS via a malicious capability to the metrics or help… CVSS 3.1MEDIUM 6.1
  • TI-2022-17390 OX App Suite through 7.10.6 allows XSS via script code within a contact that has an e-mail address but lacks a name. CVSS 3.1MEDIUM 6.1
See all 317 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences