CVE-2026-116270: MIME-tools (Perl module) · Inefficient Algorithmic Complexity
Affects MIME-tools (Perl module)Source CVE Database V5
Not known to be exploited : upgrade to 5.521 soon.
Data as of 28 Oct 2026, 17:57 UTC
Rated High by Threat Radar's AI analysis · CVSS not yet scored by NVD
- Patch
- Available – fixed in 5.521
Exploitation evidence
Disclosed: evidence found.
CVE published 28 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade MIME-tools (Perl module) to 5.521.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| MIME-tools | Affected
| Fixed in
|
CPANMIME-toolspkg:cpan/MIME-toolsOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade to MIME-tools version 5.521 or later, where this vulnerability is fixed. No other mitigation is required as the fix addresses the root cause of the memory exhaustion.
Description
MIME::Words versions before 5.521 for Perl contain an inefficient algorithmic complexity vulnerability in the decode_mimewords function. This flaw allows memory exhaustion via repeated "=?" sequences. Each incomplete encoded word starting with "=?" causes an error message containing the entire input string to be appended repeatedly, leading to large memory consumption. From version 5.518, MIME::Parser decodes every multipart boundary similarly, enabling a remote sender to exhaust memory with a crafted Content-Type header.