Description
A vulnerability, which was classified as problematic, was found in UPX up to 5.0.0. Affected is the function PackLinuxElf64::un_DT_INIT of the file src/p_lx_elf.cpp. The manipulation leads to heap-based buffer overflow. It is possible to launch the attack on the local host. The exploit has been disclosed to the public and may be used. The patch is identified as e0b6ff192412f5bb5364c1948f4f6b27a0cd5ea2. It is recommended to apply a patch to fix this issue.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| — | UPX | 5.0 | — |
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 | 4.2.4-1.1 | — |
| Debian 13 | upx-ucl | 4.2.4-1.1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | upx-ucl | No fix yet | — |
| Ubuntu 26.04 LTS | upx-ucl | No fix yet | — |
| Ubuntu 25.10 | upx-ucl | No fix yet | — |
| Ubuntu 24.04 LTS | upx-ucl | No fix yet | — |
| Ubuntu 22.04 LTS | upx-ucl | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | upx-ucl | No fix yet | — |
| Ubuntu 18.04 LTS | upx-ucl | No fix yet | — |
| Ubuntu 16.04 LTS | upx-ucl | No fix yet | — |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | upx | 5.0.0-2.1 | openSUSE-SU-2025:14947-1 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | upx-doc | 5.0.1-r0 | — |
Advisories 1
- openSUSE-SU-2025:14947-1 upx-5.0.0-2.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
References
- VDB-301494 | UPX p_lx_elf.cpp un_DT_INIT heap-based overflow vdb-entry technical-description
- VDB-301494 | CTI Indicators (IOB, IOC, IOA) signature permissions-required
- Submit #522371 | upx 5.0.0 Buffer Overflow third-party-advisory
- https://github.com/upx/upx/issues/898 issue-tracking
- https://github.com/upx/upx/issues/898#issuecomment-2734082143 issue-tracking
- https://github.com/user-attachments/files/19307868/input.zip exploit
- https://github.com/upx/upx/commit/e0b6ff192412f5bb5364c1948f4f6b27a0cd5ea2 patch