CPANSA-MIME-tools-2026-116269: MIME-tools vulnerability
| Publisher | giterlizzi | Document category | csaf_security_advisory |
|---|---|---|---|
| Initial release date | 2026-10-28T00:00:00 | Engine | CSAF Perl Toolkit 0.26 |
| Current release date | 2026-10-28T00:00:00 | Build Date | |
| Current version | 1 | Status | final |
| CVSS v3.1 Base Score | Severity | ||
| Original language | Language | en | |
| Also referred to | |||
Vulnerability Description
MIME::Field::ParamVal versions before 5.521 for Perl turn an RFC 2231 filename with a hyphenated language tag into an empty recommended filename.
A parameter such as filename*=utf-8'en-US'payload.exe is converted to an encoded word with the language tag appended to the charset. The decoder strips the language suffix only when it is a single word, so it cannot resolve the charset UTF-8*EN-US and returns an empty string. The recommended_filename() method returns that empty string rather than falling back to the name parameter.
Other mail readers return payload.exe. A remote sender can get an attachment past a policy that checks file extensions on the recommended filename.
Vulnerabilities
CVE-2026-116269
Vulnerability DescriptionMIME::Field::ParamVal versions before 5.521 for Perl turn an RFC 2231 filename with a hyphenated language tag into an empty recommended filename.
A parameter such as filename*=utf-8'en-US'payload.exe is converted to an encoded word with the language tag appended to the charset. The decoder strips the language suffix only when it is a single word, so it cannot resolve the charset UTF-8*EN-US and returns an empty string. The recommended_filename() method returns that empty string rather than falling back to the name parameter.
Other mail readers return payload.exe. A remote sender can get an attachment past a policy that checks file extensions on the recommended filename.
| Weakness | CWE-436 : Interpretation Conflict |
|---|
Product status
Known affected
| Product | Score | ||||
|---|---|---|---|---|---|
| MIME-tools less than 5.521 |
|
Fixed
- MIME-tools greater than or equal 5.521
giterlizzi
Namespace: https://github.com/giterlizzi/
gdt@cpan.org
References
- CPANSA-MIME-tools-2026-116269 JSON self
https://raw.githubusercontent.com/giterlizzi/perl-CPANSA-CSAF/develop/csaf/white/2026/cpansa-mime-tools-2026-116269.json - https://metacpan.org/release/DSKOLL/MIME-tools-5.521/changes external
https://metacpan.org/release/DSKOLL/MIME-tools-5.521/changes - CVE-2026-116269 (NVD) external
https://nvd.nist.gov/vuln/detail/CVE-2026-116269
Revision history
| Version | Date of the revision | Summary of the revision |
|---|---|---|
| 1 | Wed Oct 28 00:00:00 2026 | First release |
Sharing rules
TLP:WHITE
For the TLP version see: https://www.first.org/tlp/