Answer in brief
CVE-2026-4926 records a High severity (CVSS 7.5) vulnerability in path-to-regexp vulnerable to Denial of Service via sequential optional groups. The current sources do not mark it as known exploited. The current feed maps path-to-regexp/path-to-regexp (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-2026-4926 records a High severity (CVSS 7.5) vulnerability in path-to-regexp vulnerable to Denial of Service via sequential optional groups. The current sources do not mark it as known exploited. The current feed maps path-to-regexp/path-to-regexp (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 path-to-regexp/path-to-regexp (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:a:pillarjs:path-to-regexp:*:*:*:*:*:node.js:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| path-to-regexp/path-to-regexpgeneric | >=8.0.0 <8.4.0 | 8.4.0 |
Published upstream
Mar 26, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 10, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 9, 2026
Impact: A bad regular expression is generated any time you have multiple sequential optional groups (curly brace syntax), such as `{a}{b}{c}:z`. The generated regex grows exponentially with the number of groups, causing denial of service. Patches: Fixed in version 8.4.0. Workarounds: Limit the number of sequential optional groups in route patterns. Avoid passing user-controlled input as route patterns.
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 path-to-regexp/path-to-regexp (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:a:pillarjs:path-to-regexp:*:*:*:*:*:node.js:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| path-to-regexp/path-to-regexpgeneric | >=8.0.0 <8.4.0 | 8.4.0 |
Published upstream
Mar 26, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 10, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 9, 2026
Impact: A bad regular expression is generated any time you have multiple sequential optional groups (curly brace syntax), such as `{a}{b}{c}:z`. The generated regex grows exponentially with the number of groups, causing denial of service. Patches: Fixed in version 8.4.0. Workarounds: Limit the number of sequential optional groups in route patterns. Avoid passing user-controlled input as route patterns.
Quoted source text, attributed separately from HOL analysis.