Answer in brief
CVE-2026-42504 records a Unknown severity vulnerability in Quadratic complexity in WordDecoder.DecodeHeader in mime. The current sources do not mark it as known exploited. The current feed maps Go standard library/mime (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 Go standard library/mime (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Go standard library/mimegeneric | >=0 <1.25.11 || >=1.26.0-0 <1.26.4 | 1.25.11, 1.26.4 |
Published upstream
Jun 2, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 10, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 10, 2026
Decoding a maliciously-crafted MIME header containing many invalid encoded-words can consume excessive CPU.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-42504 records a Unknown severity vulnerability in Quadratic complexity in WordDecoder.DecodeHeader in mime. The current sources do not mark it as known exploited. The current feed maps Go standard library/mime (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 Go standard library/mime (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Go standard library/mimegeneric | >=0 <1.25.11 || >=1.26.0-0 <1.26.4 | 1.25.11, 1.26.4 |
Published upstream
Jun 2, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 10, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 10, 2026
Decoding a maliciously-crafted MIME header containing many invalid encoded-words can consume excessive CPU.
Quoted source text, attributed separately from HOL analysis.