{"cve":"CVE-2026-90203","nvd":{"published":"2026-09-17T17:17:15.320","modified":"2026-10-19T09:19:10.377","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nSquashfs: check block offset is not negative\n\nIf a negative offset is read off disk (for example the offset into the\ndecompressed fragment block), this will cause squashfs_copy_data() to\nperform an out of bounds access.\n\nFix by checking if offset is negative, and returning 0.  This matches\nexisting behaviour where an offset beyond the block returns 0 bytes\ncopied.\n\nTo trigger this out of bounds access requires a crafted Squashfs\nfilesystem and CAP_SYS_ADMIN to mount it.  Unprivileged users will not be\nable to mount such a filesystem, but once mounted, an unprivileged user\ncan trigger the out of bounds access by reading the crafted file with the\nnegative offset.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H","score":7.1},"cwes":[],"references":["https://git.kernel.org/stable/c/3d2f0cb66c909ea2312cdef465165bb9a3ba2d84","https://git.kernel.org/stable/c/95dadf366c117dcdca78a570e6832071deab1ecd","https://git.kernel.org/stable/c/b169185d5c672b989985c6c2e38cafab2548ba88","https://git.kernel.org/stable/c/bbb2218eb072b0a15dc063929200183bd23c2344","https://git.kernel.org/stable/c/c2a126fca820ae74872da28de68dc74d4595dc4b"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:55:23.253742848+00:00"},"epss":{"cve":"CVE-2026-90203","score":0.00171,"percentile":0.06466,"date":"2026-10-25"},"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."]}