Description
A flaw was found in mbsync in isync 1.4.0 through 1.4.3. Due to an unchecked condition, a malicious or compromised IMAP server could use a crafted mail message that lacks headers (i.e., one that starts with an empty line) to provoke a heap overflow, which could conceivably be exploited for remote code execution.
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 | isync | 1.4.4-1 | — |
| Debian 13 | isync | 1.4.4-1 | — |
| Debian 12 | isync | 1.4.4-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | isync | No fix yet | — |
| Ubuntu 26.04 LTS | isync | No fix yet | — |
| Ubuntu 25.10 | isync | No fix yet | — |
| Ubuntu 24.04 LTS | isync | No fix yet | — |
| Ubuntu 22.04 LTS | isync | No fix yet | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | isync | No fix yet | — |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | isync | 1.4.4-1.1 | openSUSE-SU-2024:11779-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | isync | 1.4.4-r0 | — |
| Alpine v3.23 | isync | 1.4.4-r0 | — |
| Alpine v3.22 | isync | 1.4.4-r0 | — |
| Alpine v3.21 | isync | 1.4.4-r0 | — |
| Alpine v3.20 | isync | 1.4.4-r0 | — |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | isync | 1.4.4-r0 | — |
| Alpine v3.18 | isync | 1.4.4-r0 | — |
| Alpine v3.17 | isync | 1.4.4-r0 | — |
| Alpine v3.16 | isync | 1.4.4-r0 | — |
| Alpine v3.15 | isync | 1.4.4-r0 | — |
Advisories 1
- openSUSE-SU-2024:11779-1 isync-1.4.4-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
References
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=999804
- https://sourceforge.net/p/isync/isync/ref/master/tags/
- https://sourceforge.net/p/isync/isync/commit_browser
- [oss-security] 20211203 CVE-2021-44143: heap overflow in isync/mbsync mailing-list
- FEDORA-2021-577129851b vendor-advisory
- FEDORA-2021-b7fdb7e69a vendor-advisory
- GLSA-202208-15 vendor-advisory