{"cve":"CVE-2017-17821","nvd":{"published":"2017-12-21T03:29:00.630","modified":"2026-06-17T01:11:42.767","status":"Modified","description":"WTF/wtf/FastBitVector.h in WebKit, as distributed in Safari Technology Preview Release 46, allows remote attackers to cause a denial of service (buffer overflow) or possibly have unspecified other impact because it calls the FastBitVectorWordOwner::resizeSlow function (in WTF/wtf/FastBitVector.cpp) for a purpose other than initializing a bitvector size, and resizeSlow mishandles cases where the old array length is greater than the new array length.","cvss_v4":null,"cvss_v3":{"version":"3.0","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8},"cwes":["CWE-119"],"references":["https://bugs.webkit.org/show_bug.cgi?id=181020","https://github.com/dwfault/PoCs/blob/master/WebKit%20Misuse%20of%20WTF:wtf:FastBitVector%20result%20in%20potential%20BOF/WebKit%20Misuse%20of%20WTF:wtf:FastBitVector%20result%20in%20potential%20BOF.md","https://bugs.webkit.org/show_bug.cgi?id=181020","https://github.com/dwfault/PoCs/blob/master/WebKit%20Misuse%20of%20WTF:wtf:FastBitVector%20result%20in%20potential%20BOF/WebKit%20Misuse%20of%20WTF:wtf:FastBitVector%20result%20in%20potential%20BOF.md"],"products":["apple:safari"],"source":"nvd","synced_at":"2026-10-19T20:47:56.471723566+00:00"},"epss":{"cve":"CVE-2017-17821","score":0.01379,"percentile":0.72113,"date":"2026-10-31"},"kev":null,"osv":[],"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."]}