CVE-2026-46510
CVE-2026-46510 is a high-severity vulnerability with a CVSS 3.x base score of 8.2. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-1321.
Key facts
- Severity: High (CVSS 3.x base score 8.2)
- EPSS exploit prediction: 0% (20th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-33321
- Weakness: CWE-1321
- Published:
- Last modified:
Description
form-data-objectizer converts FormData to object. Prior to 1.0.1, form-data-objectizer walks bracket-notation form keys (e.g. name[sub]) into nested objects without filtering __proto__, constructor, or prototype. A single HTTP form field whose name starts with __proto__[...] causes the library to mutate Object.prototype, which is a prototype pollution primitive of the entire Node.js process. This vulnerability is fixed in 1.0.1.
Frequently asked questions
- What is CVE-2026-46510?
- form-data-objectizer converts FormData to object. Prior to 1.0.1, form-data-objectizer walks bracket-notation form keys (e.g. name[sub]) into nested objects without filtering __proto__, constructor, or prototype. A single HTTP form field whose name starts with __proto__[...] causes the library to mutate Object.prototype, which is a prototype pollution primitive of the entire Node.js process. This vulnerability is fixed in 1.0.1.
- How severe is CVE-2026-46510?
- CVE-2026-46510 has a CVSS 3.x base score of 8.2, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability low.
- Is CVE-2026-46510 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-46510?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2026-46510 have an EU (EUVD) identifier?
- Yes. CVE-2026-46510 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-33321.
- When was CVE-2026-46510 published?
- CVE-2026-46510 was published on 2026-05-29 and last updated on 2026-06-17.
References
- https://github.com/kaspernj/form-data-objectizer/commit/7c54b99408e6e9cd6533b7245bf197dadc2a2dbc
- https://github.com/kaspernj/form-data-objectizer/security/advisories/GHSA-m2hg-wjq3-28wq
Other CWE-1321 (Prototype Pollution) vulnerabilities
- CVE-2026-25142 — Critical (CVSS 10.0): SandboxJS is a JavaScript sandboxing library. Prior to 0.8.27, SanboxJS does not properly restrict __lookupGetter__…
- CVE-2024-39008 — Critical (CVSS 10.0): robinweser fast-loops v1.1.3 was discovered to contain a prototype pollution via the function objectMergeDeep. This…
- CVE-2024-38999 — Critical (CVSS 10.0): jrburke requirejs v2.3.6 was discovered to contain a prototype pollution via the function s.contexts._.configure. This…
- CVE-2022-29823 — Critical (CVSS 10.0): Feather-Sequalize cleanQuery method uses insecure recursive logic to filter unsupported keys from the query object.…
- CVE-2022-24760 — Critical (CVSS 10.0): Parse Server is an open source http web server backend. In versions prior to 4.10.7 there is a Remote Code Execution…
- CVE-2020-12079 — Critical (CVSS 10.0): Beaker before 0.8.9 allows a sandbox escape, enabling system access and code execution. This occurs because Electron…