Answer in brief
CVE-2026-21720 records a High severity (CVSS 7.5) vulnerability in Unauthenticated DoS: avatar cache leaks goroutines when /avatar/:hash requests time out. The current sources do not mark it as known exploited. The current feed maps Grafana/grafana/grafana (generic), Grafana/grafana/grafana (generic), Grafana/grafana/grafana (generic), Grafana/grafana/grafana (generic) and additional mapped packages. 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 Grafana/grafana/grafana (generic), Grafana/grafana/grafana (generic), Grafana/grafana/grafana (generic), Grafana/grafana/grafana (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Grafana/grafana/grafanageneric | >=3.0.0 <11.6.9 | 11.6.9 |
| Grafana/grafana/grafanageneric | >=3.0.0 <12.0.8 | 12.0.8 |
| Grafana/grafana/grafanageneric | >=3.0.0 <12.1.5 | 12.1.5 |
| Grafana/grafana/grafanageneric | >=3.0.0 <12.2.3 | 12.2.3 |
| Grafana/grafana/grafanageneric | >=3.0.0 <12.3.1 | 12.3.1 |
| Grafana/grafana/grafana-enterprisegeneric | >=3.0.0 <11.6.9 | 11.6.9 |
| Grafana/grafana/grafana-enterprisegeneric | >=3.0.0 <12.0.8 | 12.0.8 |
| Grafana/grafana/grafana-enterprisegeneric | >=3.0.0 <12.1.5 | 12.1.5 |
| Grafana/grafana/grafana-enterprisegeneric | >=3.0.0 <12.2.3 | 12.2.3 |
| Grafana/grafana/grafana-enterprisegeneric | >=3.0.0 <12.3.1 | 12.3.1 |
Published upstream
Jan 27, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 29, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 15, 2026
Every uncached /avatar/:hash request spawns a goroutine that refreshes the Gravatar image. If the refresh sits in the 10-slot worker queue longer than three seconds, the handler times out and stops listening for the result, so that goroutine blocks forever trying to send on an unbuffered channel. Sustained traffic with random hashes keeps tripping this timeout, so goroutine count grows linearly, eventually exhausting memory and causing Grafana to crash on some systems.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-21720 records a High severity (CVSS 7.5) vulnerability in Unauthenticated DoS: avatar cache leaks goroutines when /avatar/:hash requests time out. The current sources do not mark it as known exploited. The current feed maps Grafana/grafana/grafana (generic), Grafana/grafana/grafana (generic), Grafana/grafana/grafana (generic), Grafana/grafana/grafana (generic) and additional mapped packages. 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 Grafana/grafana/grafana (generic), Grafana/grafana/grafana (generic), Grafana/grafana/grafana (generic), Grafana/grafana/grafana (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Grafana/grafana/grafanageneric | >=3.0.0 <11.6.9 | 11.6.9 |
| Grafana/grafana/grafanageneric | >=3.0.0 <12.0.8 | 12.0.8 |
| Grafana/grafana/grafanageneric | >=3.0.0 <12.1.5 | 12.1.5 |
| Grafana/grafana/grafanageneric | >=3.0.0 <12.2.3 | 12.2.3 |
| Grafana/grafana/grafanageneric | >=3.0.0 <12.3.1 | 12.3.1 |
| Grafana/grafana/grafana-enterprisegeneric | >=3.0.0 <11.6.9 | 11.6.9 |
| Grafana/grafana/grafana-enterprisegeneric | >=3.0.0 <12.0.8 | 12.0.8 |
| Grafana/grafana/grafana-enterprisegeneric | >=3.0.0 <12.1.5 | 12.1.5 |
| Grafana/grafana/grafana-enterprisegeneric | >=3.0.0 <12.2.3 | 12.2.3 |
| Grafana/grafana/grafana-enterprisegeneric | >=3.0.0 <12.3.1 | 12.3.1 |
Published upstream
Jan 27, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 29, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 15, 2026
Every uncached /avatar/:hash request spawns a goroutine that refreshes the Gravatar image. If the refresh sits in the 10-slot worker queue longer than three seconds, the handler times out and stops listening for the result, so that goroutine blocks forever trying to send on an unbuffered channel. Sustained traffic with random hashes keeps tripping this timeout, so goroutine count grows linearly, eventually exhausting memory and causing Grafana to crash on some systems.
Quoted source text, attributed separately from HOL analysis.