Description
report_vbuild in report.c in Fetchmail before 6.4.20 sometimes omits initialization of the vsnprintf va_list argument, which might allow mail servers to cause a denial of service or possibly have unspecified other impact via long error messages. NOTE: it is unclear whether use of Fetchmail on any realistic platform results in an impact beyond an inconvenience to the client user.
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 | fetchmail | 6.4.16-4 | — |
| Debian 13 | fetchmail | 6.4.16-4 | — |
| Debian 12 | fetchmail | 6.4.16-4 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | fetchmail | 6.6.6-1ubuntu0.1 | USN-9013-1 |
| Ubuntu 26.04 LTS | fetchmail | 6.6.2-2ubuntu0.1 | USN-9013-1 |
| Ubuntu 24.04 LTS | fetchmail | 6.4.38-1ubuntu4.2 | USN-9013-1 |
| Ubuntu 22.04 LTS | fetchmail | 6.4.27-1ubuntu0.2 | USN-9013-1 |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | fetchmail | 6.4.2-2ubuntu0.1~esm1 | USN-9013-1 |
| Ubuntu Pro 18.04 LTS | fetchmail | 6.3.26-3ubuntu0.1~18.04.1+esm1 | USN-9013-1 |
| Ubuntu Pro 16.04 LTS | fetchmail | 6.3.26-2ubuntu0.1~esm1 | USN-9013-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | fetchmail | 6.4.24-1.el8 | RHSA-2022:1964 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 8 | fetchmail | 6.4.24-1.el8 | ALSA-2022:1964 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | fetchmail | 6.4.24-1.el8 | RLSA-2022:1964 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP3 | fetchmail | 6.3.26-20.14.1 | SUSE-SU-2021:4018-1, SUSE-SU-2021:2791-1 |
| SLES 15 SP2 | fetchmail | 6.3.26-20.14.1 | SUSE-SU-2021:4018-1, SUSE-SU-2021:2791-1 |
| SLES 15 SP1 | fetchmail | 6.3.26-20.14.1 | SUSE-SU-2021:4018-1, SUSE-SU-2021:2791-1 |
| SLES 15 | fetchmail | 6.3.26-20.14.1 | SUSE-SU-2021:4018-1, SUSE-SU-2021:2791-1 |
| SLES 12 SP5 | fetchmail | 6.3.26-13.12.1 | SUSE-SU-2024:3006-1, SUSE-SU-2021:2771-1 |
Show 17 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP4 | fetchmail | 6.3.26-13.12.1 | SUSE-SU-2021:2771-1 |
| SLES 12 SP3 | fetchmail | 6.3.26-13.12.1 | SUSE-SU-2021:2771-1 |
| SLES 12 SP2 | fetchmail | 6.3.26-13.12.1 | SUSE-SU-2021:2771-1 |
| SLES for SAP 15 SP1 | fetchmail | 6.3.26-20.14.1 | SUSE-SU-2021:4018-1, SUSE-SU-2021:2791-1 |
| SLES for SAP 15 | fetchmail | 6.3.26-20.14.1 | SUSE-SU-2021:4018-1, SUSE-SU-2021:2791-1 |
| SLES for SAP 12 SP5 | fetchmail | 6.3.26-13.12.1 | SUSE-SU-2024:3006-1, SUSE-SU-2021:2771-1 |
| SLES for SAP 12 SP4 | fetchmail | 6.3.26-13.12.1 | SUSE-SU-2021:2771-1 |
| SLES for SAP 12 SP3 | fetchmail | 6.3.26-13.12.1 | SUSE-SU-2021:2771-1 |
| SLE HPC 15 SP1 | fetchmail | 6.3.26-20.14.1 | SUSE-SU-2021:4018-1, SUSE-SU-2021:2791-1 |
| SLE HPC 15 | fetchmail | 6.3.26-20.14.1 | SUSE-SU-2021:4018-1, SUSE-SU-2021:2791-1 |
| SUSE OpenStack Cloud Crowbar 9 | fetchmail | 6.3.26-13.12.1 | SUSE-SU-2021:2771-1 |
| SUSE OpenStack Cloud 9 | fetchmail | 6.3.26-13.12.1 | SUSE-SU-2021:2771-1 |
| SUSE OpenStack Cloud 8 | fetchmail | 6.3.26-13.12.1 | SUSE-SU-2021:2771-1 |
| SUSE Manager Server 4.0 | fetchmail | 6.3.26-20.14.1 | SUSE-SU-2021:2791-1 |
| SUSE Manager Retail Branch Server 4.0 | fetchmail | 6.3.26-20.14.1 | SUSE-SU-2021:2791-1 |
| SUSE Manager Proxy 4.0 | fetchmail | 6.3.26-20.14.1 | SUSE-SU-2021:2791-1 |
| SUSE Enterprise Storage 6 | fetchmail | 6.3.26-20.14.1 | SUSE-SU-2021:4018-1, SUSE-SU-2021:2791-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | fetchmail | 6.4.21-2.1 | openSUSE-SU-2024:10753-1 |
| openSUSE Leap 15.3 | fetchmail | 6.3.26-20.14.1 | openSUSE-SU-2021:4018-1, openSUSE-SU-2021:2791-1 |
| openSUSE Leap 15.2 | fetchmail | 6.3.26-lp152.6.6.1 | openSUSE-SU-2021:1591-1, openSUSE-SU-2021:1183-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | fetchmail | 6.4.20-r0 | — |
| Alpine v3.23 | fetchmail | 6.4.20-r0 | — |
| Alpine v3.22 | fetchmail | 6.4.20-r0 | — |
| Alpine v3.21 | fetchmail | 6.4.20-r0 | — |
| Alpine v3.20 | fetchmail | 6.4.20-r0 | — |
Show 6 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | fetchmail | 6.4.20-r0 | — |
| Alpine v3.18 | fetchmail | 6.4.20-r0 | — |
| Alpine v3.17 | fetchmail | 6.4.20-r0 | — |
| Alpine v3.16 | fetchmail | 6.4.20-r0 | — |
| Alpine v3.15 | fetchmail | 6.4.20-r0 | — |
| Alpine v3.14 | fetchmail | 6.4.20-r0 | — |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 2 (CBL-Mariner) | fetchmail | 6.4.22-1 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | fetchmail | 6.4.24-1.el8 | ELSA-2022-1964 |
Advisories 15
- USN-9013-1 fetchmail vulnerabilities Ubuntu Security Notices (USN) · Nov 11, 2026
- ALSA-2022:1964 Moderate: fetchmail security update AlmaLinux Security Advisories · Oct 29, 2026
- RLSA-2022:1964 Moderate: fetchmail security update Rocky Linux Security Advisories · Feb 4, 2026
- SUSE-SU-2021:2791-1 Security update for fetchmail SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:1591-1 Security update for fetchmail SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:2791-1 Security update for fetchmail SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:1183-1 Security update for fetchmail SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:4018-1 Security update for fetchmail SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:3006-1 Security update for fetchmail SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2771-1 Security update for fetchmail SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:4018-1 Security update for fetchmail SUSE / openSUSE Security Updates · Feb 4, 2026
- RHSA-2022:1964 Red Hat Security Advisory: fetchmail security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- openSUSE-SU-2024:10753-1 fetchmail-6.4.21-2.1 on GA media SUSE / openSUSE Security Updates · May 7, 2025
- WID-SEC-2022-1525 fetchmail: Schwachstelle ermöglicht Denial of Service BSI CERT-Bund (WID) · Aug 25, 2024
- ELSA-2022-1964 Moderate: fetchmail security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · May 17, 2022
References
- https://www.fetchmail.info/security.html
- http://www.openwall.com/lists/oss-security/2021/07/28/5
- https://www.fetchmail.info/fetchmail-SA-2021-01.txt
- [oss-security] 20210809 fetchmail 6.4.21 released/regression fix for 6.4.20's security fix, and UPDATE: fetchmail <= 6.4.19 security announcement 2021-01 (CVE-2021-36386) mailing-list
- FEDORA-2021-47893f53ed vendor-advisory
- FEDORA-2021-b904d99ce5 vendor-advisory
- GLSA-202209-14 vendor-advisory