Description
The apt package in Debian jessie before 1.0.9.8.4, in Debian unstable before 1.4~beta2, in Ubuntu 14.04 LTS before 1.0.1ubuntu2.17, in Ubuntu 16.04 LTS before 1.2.15ubuntu0.2, and in Ubuntu 16.10 before 1.3.2ubuntu0.1 allows man-in-the-middle attackers to bypass a repository-signing protection mechanism by leveraging improper error handling when validating InRelease file signatures.
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 | apt | 1.4~beta2 | — |
| Debian 13 | apt | 1.4~beta2 | — |
| Debian 12 | apt | 1.4~beta2 | — |
| Debian 8 | apt | 1.0.9.8.4 | DSA-3733-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | apt | 1.2.15ubuntu0.2 | USN-3156-1 |
| Ubuntu 14.04 LTS | apt | 1.0.1ubuntu2.17 | USN-3156-1 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Exploit-DB 1
- APT - Repository Signing Bypass via Memory Allocation Failure EDB-40916 · remote · Dec 14, 2016 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 2
- USN-3156-1 apt vulnerability Ubuntu Security Notices (USN) · Apr 22, 2026
- DSA-3733-1 apt - security update Debian Security (DSA / DLA) · Mar 9, 2026