{"id":"CVE-2026-90203","published":"2026-09-17T17:17:15.320","lastModified":"2026-09-18T18:17:46.120","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.","cvssScore":7.1,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H","cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/3d2f0cb66c909ea2312cdef465165bb9a3ba2d84","tags":[]},{"url":"https://git.kernel.org/stable/c/95dadf366c117dcdca78a570e6832071deab1ecd","tags":[]},{"url":"https://git.kernel.org/stable/c/b169185d5c672b989985c6c2e38cafab2548ba88","tags":[]},{"url":"https://git.kernel.org/stable/c/bbb2218eb072b0a15dc063929200183bd23c2344","tags":[]},{"url":"https://git.kernel.org/stable/c/c2a126fca820ae74872da28de68dc74d4595dc4b","tags":[]},{"url":"https://git.kernel.org/stable/c/d0a3729d464fcf516416a41cf304c0c92126ee03","tags":[]},{"url":"https://git.kernel.org/stable/c/e300eb5002925b29be803d2661af07266cfa267e","tags":[]},{"url":"https://git.kernel.org/stable/c/e4afd90bc7bf3dd477970c6c42bdd29ad3fda7fe","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}