Description
The JSON encoder in Dovecot before 2.3.5.2 allows attackers to repeatedly crash the authentication service by attempting to authenticate with an invalid UTF-8 sequence as the username.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | dovecot | 1:2.3.4.1-4 | — |
| Debian 13 | dovecot | 1:2.3.4.1-4 | — |
| Debian 12 | dovecot | 1:2.3.4.1-4 | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 | dovecot23 | 2.3.3-4.13.1 | SUSE-SU-2019:0997-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | dovecot23 | 2.3.16-1.6 | openSUSE-SU-2024:10726-1 |
| openSUSE Tumbleweed | dovecot24 | 2.4.0-1.1 | openSUSE-SU-2025:14715-1 |
| openSUSE Leap 15.0 | dovecot23 | 2.3.3-lp150.11.1 | openSUSE-SU-2019:1312-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | dovecot | 2.3.6-r0 | — |
| Alpine v3.23 | dovecot | 2.3.6-r0 | — |
| Alpine v3.22 | dovecot | 2.3.6-r0 | — |
| Alpine v3.21 | dovecot | 2.3.6-r0 | — |
| Alpine v3.20 | dovecot | 2.3.6-r0 | — |
Show 12 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | dovecot | 2.3.6-r0 | — |
| Alpine v3.18 | dovecot | 2.3.6-r0 | — |
| Alpine v3.17 | dovecot | 2.3.6-r0 | — |
| Alpine v3.16 | dovecot | 2.3.6-r0 | — |
| Alpine v3.15 | dovecot | 2.3.6-r0 | — |
| Alpine v3.14 | dovecot | 2.3.6-r0 | — |
| Alpine v3.13 | dovecot | 2.3.6-r0 | — |
| Alpine v3.12 | dovecot | 2.3.6-r0 | — |
| Alpine v3.11 | dovecot | 2.3.6-r0 | — |
| Alpine v3.10 | dovecot | 2.3.6-r0 | — |
| Alpine v3.9 | dovecot | 2.3.6-r0 | — |
| Alpine v3.8 | dovecot | 2.3.6-r0 | — |
Advisories 5
- openSUSE-SU-2019:1312-1 Security update for dovecot23 SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2025:14715-1 dovecot24-2.4.0-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10726-1 dovecot23-2.3.16-1.6 on GA media SUSE / openSUSE Security Updates · May 7, 2025
- SUSE-SU-2019:0997-1 Security update for dovecot23 SUSE / openSUSE Security Updates · May 2, 2025
- WID-SEC-2025-0241 Dovecot: Schwachstelle ermöglicht Denial of Service BSI CERT-Bund (WID) · Feb 2, 2025
References
- [oss-security] 20190418 CVE-2019-10691: JSON encoder in Dovecot 2.3 incorrecty assert-crashes when encountering invalid UTF-8 characters. mailing-list
- [dovecot-news] 20190418 CVE-2019-10691: JSON encoder in Dovecot 2.3 incorrecty assert-crashes when encountering invalid UTF-8 characters. mailing-list
- openSUSE-SU-2019:1312 vendor-advisory
- FEDORA-2019-1b61a528dd vendor-advisory
- GLSA-201908-29 vendor-advisory