Description
calibre before 5.32.0 contains a regular expression that is vulnerable to ReDoS (Regular Expression Denial of Service) in html_preprocess_rules in ebooks/conversion/preprocess.py.
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 | calibre | 5.33.0+dfsg-1 | — |
| Debian 13 | calibre | 5.33.0+dfsg-1 | — |
| Debian 12 | calibre | 5.33.0+dfsg-1 | — |
| Debian 11 | calibre | 5.12.0+dfsg-1+deb11u3 | DLA-3862-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | calibre | No fix yet | — |
| Ubuntu 22.04 LTS | calibre | No fix yet | — |
| Ubuntu 20.04 LTS | calibre | No fix yet | — |
| Ubuntu 18.04 LTS | calibre | No fix yet | — |
| Ubuntu 16.04 LTS | calibre | No fix yet | — |
Advisories 1
- DLA-3862-1 calibre - security update Debian Security (DSA / DLA) · Mar 9, 2026