Vulnerability-Lookup

CVE-2026-74866 (GCVE-0-2026-74866)

Vulnerability from cvelistv5 – Published: 2026-08-21 08:20 – Updated: 2026-08-21 12:37

Title

@fastify/busboy vulnerable to CRLF injection via multipart Content-Disposition filename and name

Summary

@fastify/busboy is a multipart form-data parser for Node.js. Its multipart part-header parser splits header lines only on the two-byte carriage-return line-feed sequence, so a lone carriage return or line feed embedded in a part header is not treated as a line break and is carried verbatim into the parsed Content-Disposition filename and field name handed to the application. An attacker who uploads a file whose filename or field name contains a bare carriage return or line feed can inject control characters into consumers that trust the parser to return clean values, enabling filesystem filename pollution, log forging, or header injection when the value is forwarded to a carriage-return-sensitive sink. All versions of @fastify/busboy up to and including 3.2.1 are affected. The issue is fixed in version 3.2.2, which rejects any header line that still contains a bare carriage return or line feed. Users should upgrade to 3.2.2, and consumers such as @fastify/multipart should bump their @fastify/busboy dependency to pull in the fix.

Severity

5.8 (Medium)


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

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-21 12:35 UTC

CWE

CWE-93 - Improper Neutralization of CRLF Sequences ('CRLF Injection')

Assigner

openjs redhat root

References

2 references

URL	Tags
https://github.com/fastify/busboy/security/adviso…
https://cna.openjsf.org/security-advisories.html

Impacted products

1 product

Vendor	Product	Version	CPE status
@fastify/busboy	@fastify/busboy	Affected: 0 , < 3.2.2 (semver) Unaffected: 3.2.2 (semver)	guessed

Credits

tonghuaroot mcollina UlisesGascon

Show details on NVD website

JSON

To clipboard

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FKIE_CVE-2026-74866

Vulnerability from fkie_nvd - Published: 2026-08-21 09:16 - Updated: 2026-08-21 13:18

Severity

5.8 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

Summary

References

	URL	Tags
	ce714d77-add3-4f53-aff5-83d477b104bb	https://cna.openjsf.org/security-advisories.html
	ce714d77-add3-4f53-aff5-83d477b104bb	https://github.com/fastify/busboy/security/advisories/GHSA-gxm5-99cw-xjw9

Impacted products

	Vendor	Product	Version

JSON

To clipboard

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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

Action not permitted

CVE-2026-74866 (GCVE-0-2026-74866)

FKIE_CVE-2026-74866

Tags

Sightings

Nomenclature