CVE-2026-116270: MIME::Words versions before 5.521 for Perl allow memory exhaustion via repeated "=?" sequences in
Source GCVE Database
Not known to be exploited : upgrade to 5.521 soon.
Data as of 28 Oct 2026, 19:29 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
A fix is available in MIME::Words version 5.521 and later. Users should upgrade to version 5.521 or newer to remediate this vulnerability. No other mitigation or workaround is indicated in the provided data.
Description
MIME::Words versions before 5.521 for Perl contain a vulnerability in the decode_mimewords function that allows memory exhaustion. This occurs when repeated "=?" sequences that do not form complete encoded words cause the function to append large error messages repeatedly, leading to significant memory consumption. From version 5.518, MIME::Parser decodes multipart boundaries using this function, enabling a remote sender to trigger this exhaustion via a crafted Content-Type header.