CVE-2026-4867
CVE Details
Visit the official vulnerability details page for CVE-2026-4867 to learn more.
Initial Publication
03/26/2026
Last Update
06/17/2026
Third Party Dependency
path-to-regexp
NIST CVE Summary
Impact:
A bad regular expression is generated any time you have three or more parameters within a single segment, separated by something that is not a period (.). For example, /:a-:b-:c or /:a-:b-:c-:d. The backtrack protection added in path-to-regexp@0.1.12 only prevents ambiguity for two parameters. With three or more, the generated lookahead does not block single separator characters, so capture groups overlap and cause catastrophic backtracking.
Patches:
Upgrade to path-to-regexp@0.1.13
Custom regex patterns in route definitions (e.g., /:a-:b([^-/]+)-:c([^-/]+)) are not affected because they override the default capture group.
Workarounds:
All versions can be patched by providing a custom regular expression for parameters after the first in a single segment. As long as the custom regular expression does not match the text before the parameter, you will be safe. For example, change /:a-:b-:c to /:a-:b([^-/]+)-:c([^-/]+).
If paths cannot be rewritten and versions cannot be upgraded, another alternative is to limit the URL length.
CVE Severity
Our Official Summary
Investigation is ongoing to determine how this vulnerability affects our products.
Status
Analyzed
Affected Products & Versions
| Version | PaletteAI | PaletteAI VerteX |
|---|---|---|
| 1.4.0 | ⚠️ Impacted | ⚠️ Impacted |
| 1.3.2 | ⚠️ Impacted | ⚠️ Impacted |
| 1.2.2 | ⚠️ Impacted | ⚠️ Impacted |
Revision History
No revisions available.