Answer in brief
CVE-2026-39458 records a High severity (CVSS 7.5) vulnerability in BIG-IP DNS Cache vulnerability. The current sources do not mark it as known exploited. The current feed maps F5/BIG-IP (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 F5/BIG-IP (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| F5/BIG-IPgeneric | >=21.0.0 <21.0.0.1 || >=17.5.0 <17.5.1.6 || >=17.1.0 <17.1.3.2 || >=16.1.0 <* | 21.0.0.1, 17.5.1.6, 17.1.3.2, * |
Published upstream
May 13, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jun 29, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jun 29, 2026
When a BIG-IP DNS profile enabled with DNS cache is configured on a virtual server, undisclosed traffic can cause the Traffic Management Microkernel (TMM) to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-39458 records a High severity (CVSS 7.5) vulnerability in BIG-IP DNS Cache vulnerability. The current sources do not mark it as known exploited. The current feed maps F5/BIG-IP (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 F5/BIG-IP (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| F5/BIG-IPgeneric | >=21.0.0 <21.0.0.1 || >=17.5.0 <17.5.1.6 || >=17.1.0 <17.1.3.2 || >=16.1.0 <* | 21.0.0.1, 17.5.1.6, 17.1.3.2, * |
Published upstream
May 13, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jun 29, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jun 29, 2026
When a BIG-IP DNS profile enabled with DNS cache is configured on a virtual server, undisclosed traffic can cause the Traffic Management Microkernel (TMM) to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
Quoted source text, attributed separately from HOL analysis.