MIME::Words versions before 5.521 for Perl allow memory exhaustion via repeated "=?" sequences in decode_mimewords
Summary
| CVE | CVE-2026-116270 |
|---|---|
| State | PUBLISHED |
| Assigner | CPANSec |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-28 18:17:13 UTC |
| Updated | 2026-10-28 18:17:13 UTC |
| 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. |
Risk And Classification
Problem Types: CWE-407 | CWE-407 CWE-407 Inefficient Algorithmic Complexity
There are no known software configurations currently associated with this CVE in NVD or the CVE Program record.
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| metacpan.org/release/DSKOLL/MIME-tools-5.521/changes | 9b29abf9-4ab0-4765-b253-1875cd9b441e | metacpan.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
Additional Advisory Data
Solutions
CNA: Upgrade to MIME-tools 5.521 or later.
There are currently no legacy QID mappings associated with this CVE.