{"cve":"CVE-2021-29945","nvd":{"published":"2021-06-24T14:15:09.763","modified":"2026-06-17T03:48:29.313","status":"Modified","description":"The WebAssembly JIT could miscalculate the size of a return type, which could lead to a null read and result in a crash. *Note: This issue only affected x86-32 platforms. Other platforms are unaffected.*. This vulnerability affects Firefox ESR < 78.10, Thunderbird < 78.10, and Firefox < 88.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","score":6.5},"cwes":["CWE-682"],"references":["https://bugzilla.mozilla.org/show_bug.cgi?id=1700690","https://www.mozilla.org/security/advisories/mfsa2021-14/","https://www.mozilla.org/security/advisories/mfsa2021-15/","https://www.mozilla.org/security/advisories/mfsa2021-16/","https://bugzilla.mozilla.org/show_bug.cgi?id=1700690"],"products":["mozilla:firefox","mozilla:firefox_esr","mozilla:thunderbird"],"source":"nvd","synced_at":"2026-10-19T21:20:07.141963181+00:00"},"epss":{"cve":"CVE-2021-29945","score":0.01202,"percentile":0.68242,"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."]}