CVE-2026-101903
From 1.16.1 until 1.20.0, the RFC 2397 regular expression allows slash characters on both sides of the media-type separator.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.44%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Axios is a promise-based HTTP client for the browser and Node.js. From 1.16.1 until 1.20.0, the RFC 2397 regular expression allows slash characters on both sides of the media-type separator. An application passes an attacker-controlled malformed data URL containing many slash characters and no comma. the JavaScript regular-expression engine explores many separator placements before rejecting the URL. Synchronous excessive backtracking can block the Node.js event loop and cause denial of service. The affected identifiers are fromDataURI, DATA_URL_PATTERN, data:. This issue is fixed in version 1.20.0.
- CVSS 4.0
- 8.2 HIGHCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.44% probability · 38th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-1333
- Source
- security-advisories@github.com
EPSS moved from 0.4% on 29 September 2026 to 0.4% on 26 October 2026.
References
- https://github.com/axios/axios/commit/d19040bda7a8be2f82c3c6e1a5bc03917daee39a
- https://github.com/axios/axios/pull/11141
- https://github.com/axios/axios/releases/tag/v1.20.0
- https://github.com/axios/axios/security/advisories/GHSA-c29m-xwm3-cm6r
- https://github.com/axios/axios/security/advisories/GHSA-c29m-xwm3-cm6r
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.