Description
canUnpack in p_vmlinx.cpp in UPX 3.95 allows remote attackers to cause a denial of service (SEGV or buffer overflow, and application crash) or possibly have unspecified other impact via a crafted UPX packed file.
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 | upx-ucl | 3.95-2 | — |
| Debian 13 | upx-ucl | 3.95-2 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | upx-ucl | No fix yet | — |
| Ubuntu 16.04 LTS | upx-ucl | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SUSE Package Hub 15 SP1 | upx | 3.96-bp151.4.3.1 | openSUSE-SU-2020:0180-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | upx | 3.96-3.2 | openSUSE-SU-2024:11486-1 |
| openSUSE Leap 15.1 | upx | 3.96-lp151.3.3.1 | openSUSE-SU-2020:0163-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | upx | 3.96-r0 | — |
| Alpine v3.23 | upx | 3.96-r0 | — |
| Alpine v3.22 | upx | 3.96-r0 | — |
| Alpine v3.21 | upx | 3.96-r0 | — |
| Alpine v3.20 | upx | 3.96-r0 | — |
Show 8 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | upx | 3.96-r0 | — |
| Alpine v3.18 | upx | 3.96-r0 | — |
| Alpine v3.17 | upx | 3.96-r0 | — |
| Alpine v3.16 | upx | 3.96-r0 | — |
| Alpine v3.15 | upx | 3.96-r0 | — |
| Alpine v3.14 | upx | 3.96-r0 | — |
| Alpine v3.13 | upx | 3.96-r0 | — |
| Alpine v3.12 | upx | 3.96-r0 | — |
Advisories 3
- openSUSE-SU-2020:0163-1 Security update for upx SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:0180-1 Security update for upx SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:11486-1 upx-3.96-3.2 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
References
- https://github.com/upx/upx/issues/287
- FEDORA-2019-9a0f02c8c8 vendor-advisory
- FEDORA-2019-bf4633142b vendor-advisory
- openSUSE-SU-2020:0163 vendor-advisory
- openSUSE-SU-2020:0180 vendor-advisory