Answer in brief
CVE-2026-42154 records a High severity (CVSS 7.5) vulnerability in Prometheus: remote read endpoint allows denial of service via crafted snappy payload. The current sources do not mark it as known exploited. The current feed maps prometheus/prometheus (generic), github.com/prometheus/prometheus (go), github.com/prometheus/prometheus (go), github.com/prometheus/prometheus (go) 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 prometheus/prometheus (generic), github.com/prometheus/prometheus (go), github.com/prometheus/prometheus (go), github.com/prometheus/prometheus (go) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:a:prometheus:prometheus:*:*:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| prometheus/prometheusgeneric | < 3.5.3 || >= 3.6.0, < 3.11.3 | Not reported |
| github.com/prometheus/prometheusgo | >=0.306.0,<0.311.3 | 0.311.3 |
| github.com/prometheus/prometheusgo | <0.305.2 | 0.305.2 |
| github.com/prometheus/prometheusgo | >=1.0.0-rc.0,<=2.5.0 | Not reported |
| github.com/prometheus/prometheusgo | >=0.306.0 <0.311.3 | 0.311.3 |
| github.com/prometheus/prometheusgo | >=0 <0.305.2 | 0.305.2 |
| github.com/prometheus/prometheusgo | >=1.0.0-rc.0 | Not reported |
| github.com/prometheus/prometheusgo | >=0 <0.305.2 >=0.306.0 <0.311.3 >=1.0.0-rc.0 | 0.305.2, 0.311.3 |
| github.com/prometheus/prometheus/v2go | >=0 | Not reported |
Published upstream
May 4, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 10, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jun 11, 2026
Prometheus is an open-source monitoring system and time series database. Prior to versions 3.5.3 and 3.11.3, the remote read endpoint (/api/v1/read) does not validate the declared decoded length in a snappy-compressed request body before allocating memory. An unauthenticated attacker can send a small payload that causes a huge heap allocation per request. Under concurrent load this can exhaust available memory and crash the Prometheus process. This issue has been patched in versions 3.5.3 and 3.11.3.
Quoted source text, attributed separately from HOL analysis.