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Public proof of conceptFix availableAwaiting NVD analysis

CVE-2026-12143

A public proof of concept exists; no exploitation attested.

  • Published2026-06-12
  • Fixed in4.0.6 · 3.0.5 · 2.5.6
  • WeaknessCWE-93

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2026-06-1219:16CVE publishedNVD

Versions per branch

OSV
form-data
BranchAffectedFixed in
4.0≥ 4.0.0, < 4.0.64.0.6
3.0≥ 3.0.0, < 3.0.53.0.5
2.5< 2.5.62.5.6

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Products declared by the CNA1 product

As harborist, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2026-06-12

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • @rootio/form-dataRoot:npmall versions · fixed in 2.3.2-root.io.1
  • @rootio/form-dataRoot:npmall versions · fixed in 2.3.3-root.io.3
  • @rootio/form-dataRoot:npmall versions · fixed in 2.3.3-root.io.4
  • @rootio/form-dataRoot:npmall versions · fixed in 2.5.1-root.io.1
  • @rootio/form-dataRoot:npmall versions · fixed in 2.5.5-root.io.1
  • @rootio/form-dataRoot:npmall versions · fixed in 3.0.1-root.io.4
  • @rootio/form-dataRoot:npmall versions · fixed in 3.0.2-root.io.2
  • @rootio/form-dataRoot:npmall versions · fixed in 3.0.3-root.io.2

167 more package ranges on OSV.dev

Vendor advisories

  • CVE-2026-12143 Red Hat Product Security499 products fixed · 36 known affected

    form-data: form-data: Form field override via CRLF injection

    network-observability/network-observability-console-plugin-pf4-rhel9 as a component of Network Observability Operator · network-observability/network-observability-console-plugin-pf5-rhel9 as a component of Network Observability Operator · network-observability/network-observability-console-plugin-rhel9 as a component of Network Observability Operator · +33 more

  • RHSA-2026:84734 Red Hat Product Security4 products fixed

    Red Hat Security Advisory: RHOAI 3.4.5 - Red Hat OpenShift AI

  • RHSA-2026:70267 Red Hat Product Security4 products fixed

    Red Hat Security Advisory: Red Hat Quay 3.14.9

  • RHSA-2026:68765 Red Hat Product Security1 product fixed

    Red Hat Security Advisory: Technical preview of the satellite/iop-vulnerability-frontend-rhel9 container image

  • RHSA-2026:68766 Red Hat Product Security1 product fixed

    Red Hat Security Advisory: General availability of the satellite/iop-remediations-rhel9 container image

  • RHSA-2026:68755 Red Hat Product Security1 product fixed

    Red Hat Security Advisory: Technical preview of the satellite/iop-vulnerability-frontend-rhel9 container image

58 more advisories

Full record on NVD

Fix

  1. Update form-data to 4.0.6 · 3.0.5 · 2.5.6
  2. Vendor fix Red Hat Product Security RHSA-2026:84734 · 4 productsFor Red Hat OpenShift AI 3.4.5 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this errata update: https://docs.redhat.com/en/documentation/red_hat_openshift_ai/
  3. Vendor fix Red Hat Product Security RHSA-2026:70267 · 4 productsBefore applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11458
  4. Vendor fix Red Hat Product Security RHSA-2026:68765 · 1 productFor Red Hat Lightspeed in Satellite installation see the Red Hat Satellite documentation.
  5. Vendor fix Red Hat Product Security RHSA-2026:66545 · 1 productBefore applying the update, back up your existing installation, including all applications, configuration files, databases and database settings. The References section of this erratum contains a download link (you must log in to download the update).
  6. Vendor fix Red Hat Product Security RHSA-2026:66003 · 1 productFor more about Ansible Portal Installer Bootc, see References links
  7. Vendor fix Red Hat Product Security RHSA-2026:63047 · 4 productsFor OpenShift Container Platform 4.19 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this asynchronous errata update: https://docs.redhat.com/en/documentation/openshift_container_platform/4.…

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CVSS 4.0 vector
CVSS:4.0/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
Published
2026-06-12
Last Modified
2026-09-11
NVD status
Awaiting Analysis
MSRC Title
form-data does not escape CR/LF/quote in multipart field names and filenames (CRLF injection)
GitHub Advisory
GHSA-hmw2-7cc7-3qxx

Frequently asked questions

What is CVE-2026-12143?

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.

Is CVE-2026-12143 actively exploited?

A proof-of-concept exploit exists for CVE-2026-12143, but active exploitation has not been confirmed at this time.

What is the CVSS score for CVE-2026-12143?

CVE-2026-12143 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

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