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CVE-2026-12143

Is CVE-2026-12143 real, exploitable, or a false positive? Here's the community verdict.

signals

public sources

Exploited in wild
Not listed
CISA KEV
Public exploit
None known
Metasploit/EDB/PoC
Base severity
7.5 High
CVSS
Exploitation prob.
0.4%
FIRST EPSS
Weakness
CWE-93
CWE

High CVSS base score, but low real-world exploitation probability (EPSS). Likely less urgent than the score implies.

baseline read

auto · not a community verdict

Real, but low real-world risk

A genuine vulnerability on paper, but EPSS shows little real-world exploitation — the base score may overstate urgency. This is not the same as a false positive.

Based on CVSS · FIRST EPSS

Confirm or dispute →

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

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.

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In your experience, is this finding real and exploitable?

awaiting field verdicts
Real, but not a risk here
Not a real issue

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Field notes & remediation

Verdicts are the quick signal. Notes are the evidence and fixes behind them.

  • 0
    Field note · TruePositive EditorialCurated

    This scores high on paper (CVSS 7.5) but the real-world signal is low. It is not in CISA KEV and no public exploit was found, and near-term exploitation looks unlikely (EPSS about 0%). Verify your own exposure before treating it as urgent. It is reachable over the network with no authentication and no user interaction, which is the most dangerous profile. Not an emergency for most teams, but patch it in your normal cycle and check whether the affected component is actually exposed in your setup.

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Same weakness: CWE-93.