Description
Mojolicious versions from 4.59 before 9.48 for Perl expose a stable representation of the session CSRF token to a BREACH compression oracle.
_csrf_token generates and caches one token per session and returns the same value on every call, and _csrf_field places that value in a hidden `csrf_token` input. When a response carrying the token also echoes attacker-controlled input and is gzip-compressed, the chosen values and the resulting compressed lengths form a BREACH oracle.
An attacker able to query it can recover the token and pass csrf_protect validation.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| SRI | Mojolicious | 4.59 – < 9.48 | 9.48 |
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 | libmojolicious-perl | 9.48+dfsg-1 | — |
| Debian 13 | libmojolicious-perl | No fix yet | — |
| Debian 12 | libmojolicious-perl | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | libmojolicious-perl | No fix yet | — |
| Ubuntu 26.04 LTS | libmojolicious-perl | No fix yet | — |
| Ubuntu 24.04 LTS | libmojolicious-perl | No fix yet | — |
| Ubuntu 22.04 LTS | libmojolicious-perl | No fix yet | — |
| Ubuntu 20.04 LTS | libmojolicious-perl | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | libmojolicious-perl | No fix yet | — |
| Ubuntu 16.04 LTS | libmojolicious-perl | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | perl-Mojolicious | 9.370.0-150700.3.3.1 | SUSE-SU-2026:4151-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | perl-Mojolicious | 9.480.0-1.1 | openSUSE-SU-2026:11282-1 |
| openSUSE Leap 16.0 | perl-Mojolicious | 9.480.0-bp160.1.1 | openSUSE-SU-2026:21496-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | perl-Test-Mojo +1 | 9.48-2.amzn2023.0.1 | ALAS2023-2026-3209 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | perl-Mojolicious | No fix yet | — |
Advisories 4
- ALAS2023-2026-3209 Moderate: perl-Mojolicious security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Oct 12, 2026
- SUSE-SU-2026:4151-1 Security update for perl-Mojolicious SUSE / openSUSE Security Updates · Sep 15, 2026
- openSUSE-SU-2026:21496-1 Security update for perl-Mojolicious SUSE / openSUSE Security Updates · Jul 31, 2026
- openSUSE-SU-2026:11282-1 perl-Mojolicious-9.480.0-1.1 on GA media SUSE / openSUSE Security Updates · Jul 16, 2026