Description
MIME::Field::ParamVal versions before 5.521 for Perl allow CPU exhaustion via unclosed comments in header parameters.
The comment pattern used to parse Content-Type and Content-Disposition parameters scans from each "(" to the next ")". In a field with no ")", every "(" scans to the end of the header and fails, so parsing takes time quadratic in the header length. The field is parsed again on each attribute lookup, several times per MIME entity.
A 40 KB header takes about 7 seconds to parse once.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| — | MIME-tools | < 5.521 | 5.521 |
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 | libmime-tools-perl | 5.522-1 | — |
| Debian 13 | libmime-tools-perl | No fix yet | — |
| Debian 12 | libmime-tools-perl | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | libmime-tools-perl | No fix yet | — |
| Ubuntu 26.04 LTS | libmime-tools-perl | No fix yet | — |
| Ubuntu 24.04 LTS | libmime-tools-perl | No fix yet | — |
| Ubuntu 22.04 LTS | libmime-tools-perl | No fix yet | — |
| Ubuntu 20.04 LTS | libmime-tools-perl | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | libmime-tools-perl | No fix yet | — |
| Ubuntu 16.04 LTS | libmime-tools-perl | No fix yet | — |
| Ubuntu 14.04 LTS | libmime-tools-perl | No fix yet | — |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | perl-MIME-tools | 5.522.0-1.1 | openSUSE-SU-2026:12347-1 |
| openSUSE Leap 16.0 | perl-MIME-tools | 5.522.0-bp160.1.1 | openSUSE-SU-2026:22226-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | perl-MIME-tools | 5.522-1.amzn2023.0.1 | ALAS2023-2026-3425 |
| Amazon Linux 2 | perl-MIME-tools | 5.505-1.amzn2.0.1 | ALAS2-2026-4095 |
Advisories 4
- ALAS2023-2026-3425 Important: perl-MIME-tools security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Nov 12, 2026
- ALAS2-2026-4095 Important: perl-MIME-tools security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Nov 12, 2026
- openSUSE-SU-2026:22226-1 Security update for perl-MIME-tools SUSE / openSUSE Security Updates · Nov 4, 2026
- openSUSE-SU-2026:12347-1 perl-MIME-tools-5.522.0-1.1 on GA media SUSE / openSUSE Security Updates · Oct 31, 2026