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.
GHSA-cgxv-575f-wxjm
MIME::Field::ParamVal versions before 5.521 for Perl allow CPU exhaustion via unclosed comments...
https://github.com/advisories/GHSA-cgxv-575f-wxjmMIME::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.
Click to expand
{
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"cveMetadata": {
"cveId": "CVE-2026-116268",
"assignerOrgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
"assignerShortName": "CPANSec",
"dateUpdated": "2026-10-28T17:33:04.336Z",
"dateReserved": "2026-10-25T18:05:02.236Z",
"datePublished": "2026-10-28T17:33:04.336Z",
"state": "PUBLISHED"
},
"containers": {
"cna": {
"providerMetadata": {
"orgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
"shortName": "CPANSec",
"dateUpdated": "2026-10-28T17:33:04.336Z"
},
"title": "MIME::Field::ParamVal versions before 5.521 for Perl allow CPU exhaustion via unclosed comments in header parameters",
"descriptions": [
{
"lang": "en",
"value": "MIME::Field::ParamVal versions before 5.521 for Perl allow CPU exhaustion via unclosed comments in header parameters.\n\nThe 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.\n\nA 40 KB header takes about 7 seconds to parse once."
}
],
"affected": [
{
"collectionURL": "https://cpan.org/modules",
"packageName": "MIME-tools",
"modules": [
"MIME::Field::ParamVal"
],
"programFiles": [
"lib/MIME/Field/ParamVal.pm"
],
"programRoutines": [
{
"name": "MIME::Field::ParamVal::parse_params"
}
],
"repo": "https://salsa.debian.org/dskoll/mime-tools",
"defaultStatus": "unaffected",
"versions": [
{
"version": "0",
"status": "affected",
"versionType": "custom",
"lessThan": "5.521"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"lang": "en",
"description": "CWE-1333 Inefficient Regular Expression Complexity",
"cweId": "CWE-1333",
"type": "CWE"
}
]
}
],
"references": [
{
"url": "https://metacpan.org/release/DSKOLL/MIME-tools-5.521/changes",
"tags": [
"release-notes"
]
}
],
"solutions": [
{
"lang": "en",
"value": "Upgrade to MIME-tools 5.521 or later."
}
]
}
}
}