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High 7.4Published Aug 28, 2026

CVE-2026-73208An 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 che…

Updated under an hour ago ()

Does this affect you?

It affects Open-Xchange GmbH OX Dovecot Pro and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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.

CVSS
7.4 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Weakness (CWE)
CWE-287
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
Deferred
Record last updated
Aug 28, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
Open-Xchange GmbH OX Dovecot Pro
open_xchange:ox_dovecot_pro (from the name)
from 2.3.13 before 2.3.22.2; from 3.0.0 before 3.0.7; from 3.1.0 before 3.1.6
CNA record
Open-Xchange GmbH OX Dovecot CE
open_xchange:ox_dovecot_ce (from the name)
from 2.3.13 before 2.4.5
CNA record

References

  • vendor-advisory

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.

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