CVE-2026-12143
form-data does not escape CR/LF/quote in multipart field names and filenames (CRLF injection)
Description
form-data is a library for creating readable multipart/form-data streams. In versions through 4.0.5, the `field` argument to `FormData#append` and the `filename` option are concatenated verbatim into the `Content-Disposition` header without escaping carriage return (CR), line feed (LF), or double-quote (") characters. An application that passes attacker-controlled data as a field name or filename (for example, an API gateway that turns JSON object keys into multipart field names) allows the attacker to terminate the header line and inject additional headers, or to smuggle entire additional multipart parts, into the request the application forwards to a backend. This can let the attacker add or override form fields (e.g. set `is_admin=true`) seen by the downstream parser. This is an instance of CWE-93 (CRLF injection). The fix escapes CR, LF, and `"` as `%0D`, `%0A`, and `%22` in field names and filenames, matching the serialization browsers use per the WHATWG HTML multipart/form-data encoding algorithm. Exploitation requires the consuming application to use untrusted input as a field name or filename; applications that use only fixed/trusted field names are not affected. Fixed in 2.5.6, 3.0.5, and 4.0.6.
INFO
Published Date :
June 12, 2026, 7:16 p.m.
Last Modified :
June 12, 2026, 8:16 p.m.
Remotely Exploit :
Yes !
Source :
7ffcee3d-2c14-4c3e-b844-86c6a321a158
Affected Products
The following products are affected by CVE-2026-12143
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 7ffcee3d-2c14-4c3e-b844-86c6a321a158 | ||||
| CVSS 4.0 | HIGH | 7ffcee3d-2c14-4c3e-b844-86c6a321a158 | ||||
| CVSS 4.0 | HIGH | 7ffcee3d-2c14-4c3e-b844-86c6a321a158 |
Solution
- Update to form-data version 2.5.6 or later.
- Update to form-data version 3.0.5 or later.
- Update to form-data version 4.0.6 or later.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-12143.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-12143 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-12143
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-12143 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-12143 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 12, 2026
Action Type Old Value New Value Added Reference https://github.com/form-data/form-data/security/advisories/GHSA-hmw2-7cc7-3qxx -
New CVE Received by 7ffcee3d-2c14-4c3e-b844-86c6a321a158
Jun. 12, 2026
Action Type Old Value New Value Added Description form-data is a library for creating readable multipart/form-data streams. In versions through 4.0.5, the `field` argument to `FormData#append` and the `filename` option are concatenated verbatim into the `Content-Disposition` header without escaping carriage return (CR), line feed (LF), or double-quote (") characters. An application that passes attacker-controlled data as a field name or filename (for example, an API gateway that turns JSON object keys into multipart field names) allows the attacker to terminate the header line and inject additional headers, or to smuggle entire additional multipart parts, into the request the application forwards to a backend. This can let the attacker add or override form fields (e.g. set `is_admin=true`) seen by the downstream parser. This is an instance of CWE-93 (CRLF injection). The fix escapes CR, LF, and `"` as `%0D`, `%0A`, and `%22` in field names and filenames, matching the serialization browsers use per the WHATWG HTML multipart/form-data encoding algorithm. Exploitation requires the consuming application to use untrusted input as a field name or filename; applications that use only fixed/trusted field names are not affected. Fixed in 2.5.6, 3.0.5, and 4.0.6. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N Added CWE CWE-93 Added Reference https://cwe.mitre.org/data/definitions/93.html Added Reference https://github.com/form-data/form-data/commit/64190db548c0179e37206858e39f27cf513e9435 Added Reference https://github.com/form-data/form-data/commit/be3f3cf553978bac15a5182f1f3c3d2d38ccf229 Added Reference https://github.com/form-data/form-data/commit/c7133499c2ee1b80c678e411244f4442bf902045 Added Reference https://github.com/form-data/form-data/security/advisories/GHSA-hmw2-7cc7-3qxx Added Reference https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#multipart-form-data Added Reference https://www.npmjs.com/package/form-data