CVE-2026-116268: high-severity vulnerability in MIME-tools
MIME::Field::ParamVal versions before 5.521 for Perl allow CPU exhaustion via unclosed comments in header parameters
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5epss 0.3%
MIME::Field::ParamVal versions before 5.521 for Perl allow CPU exhaustion via unclosed comments in header parameters.
The comment pattern used to parse Content-Type and Content-Disposition parameters scans from each "(" to the next ")". In a field with no ")", every "(" scans to the end of the header and fails, so parsing takes time quadratic in the header length. The field is parsed again on each attribute lookup, several times per MIME entity.
A 40 KB header takes about 7 seconds to parse once.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
MIME-toolsRelated CVEs — MIME-tools
In the same product, most dangerous first.
CVE-2026-116273HIGHMIME::Parser versions before 5.521 for Perl set no limit on the number of message parts by default, allowing memory exhaustionEPSS 0.3%CVE-2026-116270HIGHMIME::Words versions before 5.521 for Perl allow memory exhaustion via repeated "=?" sequences in decode_mimewordsEPSS 0.3%CVE-2026-116267HIGHMIME::Parser versions before 5.521 for Perl allow memory exhaustion via indented error messages from a truncated, deeply nested messageEPSS 0.3%CVE-2026-116272MEDIUMMIME::Field::ParamVal versions before 5.521 for Perl do not flag a duplicate boundary parameter whose name contains a nested commentEPSS 0.2%CVE-2026-116269MEDIUMMIME::Field::ParamVal versions before 5.521 for Perl turn an RFC 2231 filename with a hyphenated language tag into an empty recommended filenameEPSS 0.2%CVE-2026-116266MEDIUMMIME::Head versions from 5.518 before 5.521 for Perl decode a partly encoded multipart boundary without flagging the parse as ambiguousEPSS 0.2%