{"cve":"CVE-2023-2512","nvd":{"published":"2023-05-12T11:15:13.033","modified":"2026-06-17T05:52:45.203","status":"Modified","description":"Prior to version v1.20230419.0, the FormData API implementation was subject to an integer overflow. If a FormData instance contained more than 2^31 elements, the forEach() method could end up reading from the wrong location in memory while iterating over elements. This would most likely lead to a segmentation fault, but could theoretically allow arbitrary undefined behavior.\n\n\nIn order for the bug to be exploitable, the process would need to be able to allocate 160GB of RAM. Due to this, the bug was never exploitable on the Cloudflare Workers platform, but could theoretically be exploitable on deployments of workerd running on machines with a huge amount of memory. Moreover, in order to be remotely exploited, an attacker would have to upload a single form-encoded HTTP request of at least tens of gigabytes in size. The application code would then have to use request.formData() to parse the request and formData.forEach() to iterate over this data. Due to these limitations, the exploitation likelihood was considered Low.\n\nA fix that addresses this vulnerability has been released in version v1.20230419.0 and users are encouraged to update to the latest version available.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","score":8.1},"cwes":["CWE-190","CWE-125"],"references":["https://github.com/cloudflare/workerd/releases/tag/v1.20230419.0","https://github.com/cloudflare/workerd/security/advisories/GHSA-8vx6-69vg-c46f","https://github.com/cloudflare/workerd/releases/tag/v1.20230419.0","https://github.com/cloudflare/workerd/security/advisories/GHSA-8vx6-69vg-c46f"],"products":["cloudflare:workerd"],"source":"nvd","synced_at":"2026-10-19T21:38:18.424950729+00:00"},"epss":{"cve":"CVE-2023-2512","score":0.00617,"percentile":0.49563,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-8vx6-69vg-c46f","url":"https://osv.dev/vulnerability/GHSA-8vx6-69vg-c46f","summary":"Buffer under-read in workerd","modified":"2026-07-08T06:52:58.833724613Z","packages":[{"ecosystem":"npm","name":"workerd","purl":"pkg:npm/workerd","ranges":["<1.20230419.0"],"fixed":["1.20230419.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}