CVE-2026-90203Squashfs: check block offset is not negative
- 7.1HighCVSS base score
- 0.17%Exploitation in 30 daysEPSS · top 93% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: Squashfs: check block offset is not negative If a negative offset is read off disk (for example the offset into the decompressed fragment block), this will cause squashfs_copy_data() to perform an out of bounds access. Fix by checking if offset is negative, and returning 0. This matches existing behaviour where an offset beyond the block returns 0 bytes copied. To trigger this out of bounds access requires a crafted Squashfs filesystem and CAP_SYS_ADMIN to mount it. Unprivileged users will not be able to mount such a filesystem, but once mounted, an unprivileged user can trigger the out of bounds access by reading the crafted file with the negative offset.
Timeline
ID reserved
By Linux
- 6 days later
· 6 days later
Published
- 32 days later
· 32 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.1 | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H |
| NVDNVD · Received | 3.1 | High7.1 | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.17% · top 93% of all CVEs (13 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.1.
Affected products
- affected f400e12656ab518be107febfe2315fb1eab5a342 – < b169185d5c672b989985c6c2e38cafab2548ba88
- affected f400e12656ab518be107febfe2315fb1eab5a342 – < c2a126fca820ae74872da28de68dc74d4595dc4b
- affected f400e12656ab518be107febfe2315fb1eab5a342 – < 95dadf366c117dcdca78a570e6832071deab1ecd
- affected f400e12656ab518be107febfe2315fb1eab5a342 – < 3d2f0cb66c909ea2312cdef465165bb9a3ba2d84
- affected f400e12656ab518be107febfe2315fb1eab5a342 – < bbb2218eb072b0a15dc063929200183bd23c2344
- affected f400e12656ab518be107febfe2315fb1eab5a342 – < d0a3729d464fcf516416a41cf304c0c92126ee03
- affected f400e12656ab518be107febfe2315fb1eab5a342 – < e4afd90bc7bf3dd477970c6c42bdd29ad3fda7fe
- affected f400e12656ab518be107febfe2315fb1eab5a342 – < e300eb5002925b29be803d2661af07266cfa267e
- affected 2.6.29
- unaffected < 2.6.29
- unaffected 5.10.270 – ≤ 5.10.*
- unaffected 5.15.221 – ≤ 5.15.*
- unaffected 6.1.188 – ≤ 6.1.*
- unaffected 6.6.157 – ≤ 6.6.*
- unaffected 6.12.110 – ≤ 6.12.*
- unaffected 6.18.52 – ≤ 6.18.*
- unaffected 7.2.6 – ≤ 7.2.*
- unaffected 7.3 – ≤ *
References
References8
- https://git.kernel.org/stable/c/b169185d5c672b989985c6c2e38cafab2548ba88 (opens in a new tab)
- https://git.kernel.org/stable/c/c2a126fca820ae74872da28de68dc74d4595dc4b (opens in a new tab)
- https://git.kernel.org/stable/c/95dadf366c117dcdca78a570e6832071deab1ecd (opens in a new tab)
- https://git.kernel.org/stable/c/3d2f0cb66c909ea2312cdef465165bb9a3ba2d84 (opens in a new tab)
- https://git.kernel.org/stable/c/bbb2218eb072b0a15dc063929200183bd23c2344 (opens in a new tab)
- https://git.kernel.org/stable/c/d0a3729d464fcf516416a41cf304c0c92126ee03 (opens in a new tab)
- https://git.kernel.org/stable/c/e4afd90bc7bf3dd477970c6c42bdd29ad3fda7fe (opens in a new tab)
- https://git.kernel.org/stable/c/e300eb5002925b29be803d2661af07266cfa267e (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-81796 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-90203)Record last updated .