CPANSA-MIME-tools-2026-116270: 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::Words versions before 5.521 for Perl allow memory exhaustion via repeated "=?" sequences in decode_mimewords.
For each "=?" that does not start a complete encoded word, decode_mimewords appends an error message containing the whole input string to $@. A boundary of 8,000 "=?" pairs (16,000 bytes) adds 8,000 copies of itself to $@, about 128 MB.
From version 5.518, MIME::Parser decodes every multipart boundary this way, so a remote sender can exhaust the memory of the parsing process with one Content-Type header.
Vulnerabilities
CVE-2026-116270
Vulnerability DescriptionMIME::Words versions before 5.521 for Perl allow memory exhaustion via repeated "=?" sequences in decode_mimewords.
For each "=?" that does not start a complete encoded word, decode_mimewords appends an error message containing the whole input string to $@. A boundary of 8,000 "=?" pairs (16,000 bytes) adds 8,000 copies of itself to $@, about 128 MB.
From version 5.518, MIME::Parser decodes every multipart boundary this way, so a remote sender can exhaust the memory of the parsing process with one Content-Type header.
| Weakness | CWE-407 : Inefficient Algorithmic Complexity |
|---|
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-2026-116270 JSON self
https://raw.githubusercontent.com/giterlizzi/perl-CPANSA-CSAF/develop/csaf/white/2026/cpansa-mime-tools-2026-116270.json - https://metacpan.org/release/DSKOLL/MIME-tools-5.521/changes external
https://metacpan.org/release/DSKOLL/MIME-tools-5.521/changes - CVE-2026-116270 (NVD) external
https://nvd.nist.gov/vuln/detail/CVE-2026-116270
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/