CVE-2026-98636
In the Linux kernel, the following vulnerability has been resolved: squashfs: Add dictionary size range check to prevent shift-out-of-bounds When an abnormal SquashFS image (COMP_OPTS flag is 1 but dictionary size is 0) is mounted, and performs shift operations using dictionarysize, the shift exponent is -1, causing a shift-out-of-bounds. Detail as below: squashfs_comp_opts(msblk, buffer, length) squashfs_xz_comp_opts() if (comp_opts) n = ffs(opts->dict_size) - 1;<----opts->dict_size=0, n=-1 if (opts->dict_size != (1 << n) && opts->dict_size != (1 << n) + (1 << (n + 1))) <----shift-out-of-bounds Fix it by adding a dictionary size range check before the shift operation.
Affected versions
Linux kernel versions
2.6.39
and later are affected. Fixed in
5.10.271,
5.15.222,
6.1.189,
6.6.158,
6.12.112,
6.18.55,
7.2.9,
7.3
and their respective stable series.
References
8 totalFrequently asked questions
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What is CVE-2026-98636?
CVE-2026-98636 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 2.6.39 onward and has been patched in 5.10.271, 5.15.222, 6.1.189 and others. CVE-2026-98636 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-98636?
Yes. CVE-2026-98636 has been patched. Fixed versions include 5.10.271, 5.15.222, 6.1.189 and others. If you are running Linux kernel 2.6.39 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-98636 actively exploited?
No. CVE-2026-98636 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.