Description
Microsoft Knack 0.12.0 allows Regular expression Denial of Service (ReDoS) in the knack.introspection module. option_descriptions employs an inefficient regular expression pattern: "\s(:param)\s+(.+?)\s:(.*)" that is susceptible to catastrophic backtracking when processing crafted docstrings containing a large volume of whitespace without a terminating colon. An attacker who can control or inject docstring content into affected applications can trigger excessive CPU consumption. This software is used by Azure CLI.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Microsoft | Knack | 0.12.0 | — |
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 | knack | No fix yet | — |
| Debian 13 | knack | No fix yet | — |
| Debian 12 | knack | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | knack | No fix yet | — |
| Ubuntu 26.04 LTS | knack | No fix yet | — |
| Ubuntu 25.10 | knack | No fix yet | — |
| Ubuntu 24.04 LTS | knack | No fix yet | — |
| Ubuntu 22.04 LTS | knack | No fix yet | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | knack | No fix yet | — |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | az | 2.79.0-r0 | — |
| Wolfi rolling | py3-knack +5 | 0.12.0-r3 | — |