{"id":"CVE-2026-98636","title":"squashfs: Add dictionary size range check to prevent shift-out-of-bounds","summary":"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…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= ff750311d30acc9564ef577050794953eee59f01 < b02948a23455f8190a53887b2d2c13ae1d360cea","Linux >= ff750311d30acc9564ef577050794953eee59f01 < 9d9c5c218ea356a1d88765214ad2919605280ab1","Linux >= ff750311d30acc9564ef577050794953eee59f01 < 7a1c293e7aa17f1afaee0684e0e931fe23a5a6b1","Linux >= ff750311d30acc9564ef577050794953eee59f01 < c68e0068a236f9a7dfc19720bdf11e5d80a85089","Linux >= ff750311d30acc9564ef577050794953eee59f01 < 88c673a0bd233df44ca0020da82f4fd3876de27a","Linux >= ff750311d30acc9564ef577050794953eee59f01 < 0cb85377daaefb4ce5ce72975f2deb27ee0e0cad","Linux >= ff750311d30acc9564ef577050794953eee59f01 < e1ca4e3a380ef3e8f46ce006f1146392e3f32c98","Linux >= ff750311d30acc9564ef577050794953eee59f01 < 1f7745fb3580152ca902ef181b605f33cabfb1d0","Linux 2.6.39"],"published":"2026-10-18","updated":"2026-10-18","sourceUpdated":"2026-10-18T15:20:07.184Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98636","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"}],"tags":["cve.org"],"ingestedAt":"2026-10-18T15:45:12.230Z","slug":"CVE-2026-98636","body":"## Overview\n\nIn 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.\n\n## Affected\n\n- `Linux >= ff750311d30acc9564ef577050794953eee59f01 < b02948a23455f8190a53887b2d2c13ae1d360cea`\n- `Linux >= ff750311d30acc9564ef577050794953eee59f01 < 9d9c5c218ea356a1d88765214ad2919605280ab1`\n- `Linux >= ff750311d30acc9564ef577050794953eee59f01 < 7a1c293e7aa17f1afaee0684e0e931fe23a5a6b1`\n- `Linux >= ff750311d30acc9564ef577050794953eee59f01 < c68e0068a236f9a7dfc19720bdf11e5d80a85089`\n- `Linux >= ff750311d30acc9564ef577050794953eee59f01 < 88c673a0bd233df44ca0020da82f4fd3876de27a`\n- `Linux >= ff750311d30acc9564ef577050794953eee59f01 < 0cb85377daaefb4ce5ce72975f2deb27ee0e0cad`\n- `Linux >= ff750311d30acc9564ef577050794953eee59f01 < e1ca4e3a380ef3e8f46ce006f1146392e3f32c98`\n- `Linux >= ff750311d30acc9564ef577050794953eee59f01 < 1f7745fb3580152ca902ef181b605f33cabfb1d0`\n- `Linux 2.6.39`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}