Answer in brief
CVE-2026-39820 records a High severity (CVSS 7.5) vulnerability in Quadratic string concatentation in consumeComment in net/mail. The current sources do not mark it as known exploited. The current feed maps Go standard library/net/mail (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
Answer in brief
CVE-2026-39820 records a High severity (CVSS 7.5) vulnerability in Quadratic string concatentation in consumeComment in net/mail. The current sources do not mark it as known exploited. The current feed maps Go standard library/net/mail (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.5. 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/net/mail (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:a:golang:go:*:*:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Go standard library/net/mailgeneric | >=0 <1.25.10 || >=1.26.0-0 <1.26.3 | 1.25.10, 1.26.3 |
Published upstream
May 7, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 1, 2026
Well-crafted inputs reaching ParseAddress, ParseAddressList, and ParseDate were able to trigger excessive CPU exhaustion and memory allocations.
Quoted source text, attributed separately from HOL analysis.
CVSS is 7.5. 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/net/mail (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:a:golang:go:*:*:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Go standard library/net/mailgeneric | >=0 <1.25.10 || >=1.26.0-0 <1.26.3 | 1.25.10, 1.26.3 |
Published upstream
May 7, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 1, 2026
Well-crafted inputs reaching ParseAddress, ParseAddressList, and ParseDate were able to trigger excessive CPU exhaustion and memory allocations.
Quoted source text, attributed separately from HOL analysis.