Answer in brief
CVE-2026-116270 records a Unknown severity vulnerability in MIME::Words versions before 5.521 for Perl allow memory exhaustion via repeated "=?" sequences in decode_mimewords. The current sources do not mark it as known exploited. The current feed maps MIME-tools (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps MIME-tools (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| MIME-toolsgeneric | >=0 <5.521 | 5.521 |
Published upstream
Oct 28, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 28, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 28, 2026
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.
Quoted source text, attributed separately from HOL analysis.