Description
In the Zstandard command-line utility prior to v1.4.1, output files were created with default permissions. Correct file permissions (matching the input) would only be set at completion time. Output files could therefore be readable or writable to unintended parties.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Zstandard | unspecified – < 1.4.1 | 1.4.1 |
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 | libzstd | 1.4.8+dfsg-1 | — |
| Debian 13 | libzstd | 1.4.8+dfsg-1 | — |
| Debian 12 | libzstd | 1.4.8+dfsg-1 | — |
| Debian 10 | libzstd | 1.3.8+dfsg-3+deb10u1 | DSA-4850-1 |
| Debian 9 | libzstd | 1.1.2-1+deb9u1 | DLA-2573-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | libzstd | 1.4.4+dfsg-3ubuntu0.1 | USN-4760-1 |
| Ubuntu 18.04 LTS | libzstd | 1.3.3+dfsg-2ubuntu1.2 | USN-4760-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 16.04 LTS | libzstd | 1.3.1+dfsg-1~ubuntu0.16.04.1+esm3 | USN-5720-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP2 | zstd | 1.4.4-1.6.1 | SUSE-SU-2021:0948-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLE Micro 5.0 | zstd | 1.4.4-1.6.1 | SUSE-SU-2021:0948-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.2 | zstd | 1.4.4-lp152.2.3.1 | openSUSE-SU-2021:0481-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | zstd | 1.4.1-r0 | — |
| Alpine v3.23 | zstd | 1.4.1-r0 | — |
| Alpine v3.22 | zstd | 1.4.1-r0 | — |
| Alpine v3.21 | zstd | 1.4.1-r0 | — |
| Alpine v3.20 | zstd | 1.4.1-r0 | — |
Show 6 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | zstd | 1.4.1-r0 | — |
| Alpine v3.18 | zstd | 1.4.1-r0 | — |
| Alpine v3.17 | zstd | 1.4.1-r0 | — |
| Alpine v3.16 | zstd | 1.4.1-r0 | — |
| Alpine v3.15 | zstd | 1.4.1-r0 | — |
| Alpine v3.14 | zstd | 1.4.1-r0 | — |
Advisories 6
- USN-5720-1 libzstd vulnerabilities Ubuntu Security Notices (USN) · Jun 25, 2026
- USN-4760-1 libzstd vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DSA-4850-1 libzstd - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2573-1 libzstd - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2021:0948-1 Security update for zstd SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:0481-1 Security update for zstd SUSE / openSUSE Security Updates · Feb 4, 2026