{"id":"CVE-2026-98636","state":"PUBLISHED","title":"squashfs: Add dictionary size range check to prevent shift-out-of-bounds","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsquashfs: Add dictionary size range check to prevent shift-out-of-bounds\n\nWhen an abnormal SquashFS image (COMP_OPTS flag is 1 but dictionary size\nis 0) is mounted, and performs shift operations using dictionarysize, the\nshift exponent is -1, causing a shift-out-of-bounds.\n\nDetail as below:\nsquashfs_comp_opts(msblk, buffer, length)\n  squashfs_xz_comp_opts()\n    if (comp_opts)\n      n = ffs(opts->dict_size) - 1;<----opts->dict_size=0, n=-1\n      if (opts->dict_size != (1 << n) && opts->dict_size !=\n\t  \t(1 << n) + (1 << (n + 1))) <----shift-out-of-bounds\n\nFix it by adding a dictionary size range check before the shift operation.","publishedAt":"2026-10-18T15:20:07.184Z","updatedAt":"2026-10-19T09:23:06.005Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"ff750311d30acc9564ef577050794953eee59f01","status":"affected","lessThan":"b02948a23455f8190a53887b2d2c13ae1d360cea","versionType":"git"},{"version":"ff750311d30acc9564ef577050794953eee59f01","status":"affected","lessThan":"9d9c5c218ea356a1d88765214ad2919605280ab1","versionType":"git"},{"version":"ff750311d30acc9564ef577050794953eee59f01","status":"affected","lessThan":"7a1c293e7aa17f1afaee0684e0e931fe23a5a6b1","versionType":"git"},{"version":"ff750311d30acc9564ef577050794953eee59f01","status":"affected","lessThan":"c68e0068a236f9a7dfc19720bdf11e5d80a85089","versionType":"git"},{"version":"ff750311d30acc9564ef577050794953eee59f01","status":"affected","lessThan":"88c673a0bd233df44ca0020da82f4fd3876de27a","versionType":"git"},{"version":"ff750311d30acc9564ef577050794953eee59f01","status":"affected","lessThan":"0cb85377daaefb4ce5ce72975f2deb27ee0e0cad","versionType":"git"},{"version":"ff750311d30acc9564ef577050794953eee59f01","status":"affected","lessThan":"e1ca4e3a380ef3e8f46ce006f1146392e3f32c98","versionType":"git"},{"version":"ff750311d30acc9564ef577050794953eee59f01","status":"affected","lessThan":"1f7745fb3580152ca902ef181b605f33cabfb1d0","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/squashfs/xz_wrapper.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.39","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.39","versionType":"semver"},{"version":"5.10.271","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.222","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.189","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.158","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.112","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.55","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.9","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/squashfs/xz_wrapper.c"]}],"references":["https://git.kernel.org/stable/c/b02948a23455f8190a53887b2d2c13ae1d360cea","https://git.kernel.org/stable/c/9d9c5c218ea356a1d88765214ad2919605280ab1","https://git.kernel.org/stable/c/7a1c293e7aa17f1afaee0684e0e931fe23a5a6b1","https://git.kernel.org/stable/c/c68e0068a236f9a7dfc19720bdf11e5d80a85089","https://git.kernel.org/stable/c/88c673a0bd233df44ca0020da82f4fd3876de27a","https://git.kernel.org/stable/c/0cb85377daaefb4ce5ce72975f2deb27ee0e0cad","https://git.kernel.org/stable/c/e1ca4e3a380ef3e8f46ce006f1146392e3f32c98","https://git.kernel.org/stable/c/1f7745fb3580152ca902ef181b605f33cabfb1d0"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/98xxx/CVE-2026-98636.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98636","state":"PUBLISHED","datePublished":"2026-10-18T15:20:07.184Z","dateUpdated":"2026-10-19T09:23:06.005Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.361Z"},"containers":{"cna":{"title":"squashfs: Add dictionary size range check to prevent shift-out-of-bounds","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nsquashfs: Add dictionary size range check to prevent shift-out-of-bounds\n\nWhen an abnormal SquashFS image (COMP_OPTS flag is 1 but dictionary size\nis 0) is mounted, and performs shift operations using dictionarysize, the\nshift exponent is -1, causing a shift-out-of-bounds.\n\nDetail as below:\nsquashfs_comp_opts(msblk, buffer, length)\n  squashfs_xz_comp_opts()\n    if (comp_opts)\n      n = ffs(opts->dict_size) - 1;<----opts->dict_size=0, n=-1\n      if (opts->dict_size != (1 << n) && opts->dict_size !=\n\t  \t(1 << n) + (1 << (n + 1))) <----shift-out-of-bounds\n\nFix it by adding a dictionary size range check before the shift operation."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"ff750311d30acc9564ef577050794953eee59f01","status":"affected","lessThan":"b02948a23455f8190a53887b2d2c13ae1d360cea","versionType":"git"},{"version":"ff750311d30acc9564ef577050794953eee59f01","status":"affected","lessThan":"9d9c5c218ea356a1d88765214ad2919605280ab1","versionType":"git"},{"version":"ff750311d30acc9564ef577050794953eee59f01","status":"affected","lessThan":"7a1c293e7aa17f1afaee0684e0e931fe23a5a6b1","versionType":"git"},{"version":"ff750311d30acc9564ef577050794953eee59f01","status":"affected","lessThan":"c68e0068a236f9a7dfc19720bdf11e5d80a85089","versionType":"git"},{"version":"ff750311d30acc9564ef577050794953eee59f01","status":"affected","lessThan":"88c673a0bd233df44ca0020da82f4fd3876de27a","versionType":"git"},{"version":"ff750311d30acc9564ef577050794953eee59f01","status":"affected","lessThan":"0cb85377daaefb4ce5ce72975f2deb27ee0e0cad","versionType":"git"},{"version":"ff750311d30acc9564ef577050794953eee59f01","status":"affected","lessThan":"e1ca4e3a380ef3e8f46ce006f1146392e3f32c98","versionType":"git"},{"version":"ff750311d30acc9564ef577050794953eee59f01","status":"affected","lessThan":"1f7745fb3580152ca902ef181b605f33cabfb1d0","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/squashfs/xz_wrapper.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.39","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.39","versionType":"semver"},{"version":"5.10.271","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.222","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.189","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.158","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.112","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.55","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.9","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/squashfs/xz_wrapper.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/b02948a23455f8190a53887b2d2c13ae1d360cea"},{"url":"https://git.kernel.org/stable/c/9d9c5c218ea356a1d88765214ad2919605280ab1"},{"url":"https://git.kernel.org/stable/c/7a1c293e7aa17f1afaee0684e0e931fe23a5a6b1"},{"url":"https://git.kernel.org/stable/c/c68e0068a236f9a7dfc19720bdf11e5d80a85089"},{"url":"https://git.kernel.org/stable/c/88c673a0bd233df44ca0020da82f4fd3876de27a"},{"url":"https://git.kernel.org/stable/c/0cb85377daaefb4ce5ce72975f2deb27ee0e0cad"},{"url":"https://git.kernel.org/stable/c/e1ca4e3a380ef3e8f46ce006f1146392e3f32c98"},{"url":"https://git.kernel.org/stable/c/1f7745fb3580152ca902ef181b605f33cabfb1d0"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T09:23:06.005Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.39","versionEndExcluding":"5.10.271"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.39","versionEndExcluding":"5.15.222"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.39","versionEndExcluding":"6.1.189"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.39","versionEndExcluding":"6.6.158"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.39","versionEndExcluding":"6.12.112"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.39","versionEndExcluding":"6.18.55"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.39","versionEndExcluding":"7.2.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.39","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}