CVE-2026-42008
published 2026-08-28CVE-2026-42008: Forwarding information received from a host listed as a trusted proxy is not kept separate from Dovecot's own authentication fields, so a value sent by that…
PriorityP423medium4.3CVSS 3.1
AVAACLPRNUINSUCNILAN
EPSS
0.24%
13.7th percentile
Forwarding information received from a host listed as a trusted proxy is not kept separate from Dovecot's own authentication fields, so a value sent by that host can be injected as an internal authentication field. Any host permitted to act as a trusted proxy can authenticate as any user without knowing that user's password. This affects deployments whose password database honours a field that permits authentication without a password. Deployments that do not configure trusted proxies are not affected. Restrict the list of trusted proxy networks to hosts that are fully under your control. Update to non-vulnerable version. No publicly available exploits are known.
Affected
5 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| dovecot | dovecot | — | — |
| open-xchange_gmbh | ox_dovecot_ce | >= 2.3.4 < 2.4.5 | 2.4.5 |
| open-xchange_gmbh | ox_dovecot_pro | >= 2.3.4 < 2.3.22.2 | 2.3.22.2 |
| open-xchange_gmbh | ox_dovecot_pro | >= 3.0.0 < 3.0.7 | 3.0.7 |
| open-xchange_gmbh | ox_dovecot_pro | >= 3.1.0 < 3.1.6 | 3.1.6 |
CVSS provenance
nvdv3.14.3MEDIUMCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
vendor_redhat4.3MEDIUM
Stop checking back — get the weekly exploitation signal.
Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.
GHSA
Forwarding information received from a host listed as a trusted proxy is not kept separate from Dovecot's own authentication fields, so a value sent by that host can be injected as an internal authent
ghsa_unreviewed·2026-08-28
CVE-2026-42008 [MEDIUM] CWE-287 Forwarding information received from a host listed as a trusted proxy is not kept separate from Dovecot's own authentication fields, so a value sent by that host can be injected as an internal authent
Forwarding information received from a host listed as a trusted proxy is not kept separate from Dovecot's own authentication fields, so a value sent by that host can be injected as an internal authentication field. Any host permitted to act as a trusted proxy can authenticate as any user without knowing that user's password. This affects deployments whose password database honours a field that permits authentication without a password. Deployments that do not configure trusted proxies are not affected. Restrict the list of trusted proxy networks to hosts that are fully under your control. Update to non-vulnerable version. No publicly available exploits are known.
Red Hat
dovecot: Dovecot: Authentication bypass via trusted proxy forwarding
vendor_redhat·2026-08-28·CVSS 4.3
CVE-2026-42008 [MEDIUM] CWE-349 dovecot: Dovecot: Authentication bypass via trusted proxy forwarding
dovecot: Dovecot: Authentication bypass via trusted proxy forwarding
Forwarding information received from a host listed as a trusted proxy is not kept separate from Dovecot's own authentication fields, so a value sent by that host can be injected as an internal authentication field. Any host permitted to act as a trusted proxy can authenticate as any user without knowing that user's password. This affects deployments whose password database honours a field that permits authentication without a password. Deployments that do not configure trusted proxies are not affected. Restrict the list of trusted proxy networks to hosts that are fully under your control. Update to non-vulnerable version. No publicly available exploits are known.
A flaw was found in Dovecot. Forwarded information from a
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-42008 dovecot: Dovecot: Authentication bypass via trusted proxy forwarding [fedora-all]
bugzilla·2026-09-01·CVSS 4.3
CVE-2026-42008 [MEDIUM] CVE-2026-42008 dovecot: Dovecot: Authentication bypass via trusted proxy forwarding [fedora-all]
CVE-2026-42008 dovecot: Dovecot: Authentication bypass via trusted proxy forwarding [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Forwarding information received from a host listed as a trusted proxy is not kept separate from Dovecot's own authentication fields, so a value sent by that host can be injected as an internal authentication field. Any host permitted to act as a trusted proxy can authenticate as any user without knowing that user's password. This affects deployments whose password database honours a field that permits authentication without a password. Deployments that do not configure tru
Bugzilla
CVE-2026-42008 dovecot: Dovecot: Authentication bypass via trusted proxy forwarding
bugzilla·2026-08-28·CVSS 4.3
CVE-2026-42008 [MEDIUM] CVE-2026-42008 dovecot: Dovecot: Authentication bypass via trusted proxy forwarding
CVE-2026-42008 dovecot: Dovecot: Authentication bypass via trusted proxy forwarding
Forwarding information received from a host listed as a trusted proxy is not kept separate from Dovecot's own authentication fields, so a value sent by that host can be injected as an internal authentication field. Any host permitted to act as a trusted proxy can authenticate as any user without knowing that user's password. This affects deployments whose password database honours a field that permits authentication without a password. Deployments that do not configure trusted proxies are not affected. Restrict the list of trusted proxy networks to hosts that are fully under your control. Update to non-vulnerable version. No publicly available exploits are known.
2026-08-28
Published