Header injection via unsanitized multipart content type
Published Apr 24, 2026 · Updated Apr 24, 2026
CRLF injection in Axios 1.0.0 through 1.15.0 allows remote attackers to inject MIME part headers through crafted Blob types. The FormDataPart constructor in lib/helpers/formDataToStream.js embeds Blob/File-like value.type data in each multipart Content-Type line without removing CR or LF characters. Reachability requires a Node.js service to accept an attacker-controlled MIME type and repost that object as FormData; exploitation alters headers parsed by the downstream service.
Summary
What happened
CRLF injection in Axios 1.0.0 through 1.15.0 allows remote attackers to inject MIME part headers through crafted Blob types. The FormDataPart constructor in lib/helpers/formDataToStream.js embeds Blob/File-like value.type data in each multipart Content-Type line without removing CR or LF characters. Reachability requires a Node.js service to accept an attacker-controlled MIME type and repost that object as FormData; exploitation alters headers parsed by the downstream service.
The record
- CVE
- CVE-2026-42037
- Published
- Apr 24, 2026
- Updated
- Apr 24, 2026
- Vendor
- Axios
- Product
- Axios
- Classifications
- CWE-93
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 24, 2026CVE publishedPublication date reported by the CVE source.
- Apr 24, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 1.0.0, < 1.15.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Axios multipart CRLF proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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