High severity · published Jun 8, 2026
CVE-2026-46303
isofs: validate Rock Ridge CE continuation extent against volume size
8.2
CVSS
0.3%
EPSS
No
On KEV
Description
In the Linux kernel, the following vulnerability has been resolved:
isofs: validate Rock Ridge CE continuation extent against volume size
rock_continue() reads rs->cont_extent verbatim from the Rock Ridge CE
record and passes it to sb_bread() without checking that the block
number is within the mounted ISO 9660 volume. commit e595447e177b
("[PATCH] rock.c: handle corrupted directories") added cont_offset
and cont_size rejection for the CE continuation but did not validate
the extent block number itself. commit f54e18f1b831 ("isofs: Fix
infinite looping over CE entries") later capped the CE chain length
at RR_MAX_CE_ENTRIES = 32 but again left the block number unchecked.
With a crafted ISO mounted via udisks2 (desktop optical auto-mount)
or via CAP_SYS_ADMIN mount, rs->cont_extent can therefore point at
an out-of-range block or at blocks belonging to an adjacent
filesystem on the same block device. sb_bread() on an out-of-range
block returns NULL cleanly via the block layer EIO path, so there
is no memory-safety violation. For in-range reads of adjacent-
filesystem data, the CE buffer is parsed as Rock Ridge records and
only the text of SL sub-records reaches userspace through
readlink(), which makes the info-leak channel narrow and difficult
to exploit; still, rejecting the malformed CE outright matches the
rejection shape already present in the same function for
cont_offset and cont_size.
Add an ISOFS_SB(sb)->s_nzones bounds check to rock_continue() next
to the existing offset/size rejection, printing the same
corrupted-directory-entry notice.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 25% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KE
Kernel · Linux
2.6.32.66 before 2.6.33; 3.2.67 before 3.3; 3.4.107 before 3.5; 3.10.64 before 3.11; 3.12.36 before 3.13; 3.14.28 before 3.15; +9 more · source: NVD
LI
Linux · Linux
f54e18f1b831c92f6512d2eedb224cd63d607d3d before 8356fb821016797f5677cbeee5ddc0d32a95b4be; f54e18f1b831c92f6512d2eedb224cd63d607d3d before d582e12378bc1637f337622feef762f53c43fd57; f54e18f1b831c92f6512d2eedb224cd63d607d3d before bf1bc673c587f5ef7e9c09b94aea7c5a7847d4d9; f54e18f1b831c92f6512d2eedb224cd63d607d3d before c9b37c8b73f6368e4750e5ccb0632c380b43c6e5; f54e18f1b831c92f6512d2eedb224cd63d607d3d before 22b36fa081f38ab397c7697f9d539211b51a0cfc; f54e18f1b831c92f6512d2eedb224cd63d607d3d before e69da8eeab74b4f4505024c38a17bce060fe7df8; +19 more · source: vendor
SS
SIMATIC S7-1500 CPU 1518-4 PN/DP MFP · Siemens
V3.1.6; V3.1.7; V3.1.6; V3.1.7 · source: CISA
SS
SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP · Siemens
V3.1.6; V3.1.7; V3.1.6; V3.1.7 · source: CISA
SS
SIMATIC S7-1500 TM MFP - GNU/Linux subsystem · Siemens
0 · source: CISA
SS
SIPLUS S7-1500 CPU 1518-4 PN/DP MFP · Siemens
V3.1.6; V3.1.7 · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-46303
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-46303
Patch
https://git.kernel.org/stable/c/22b36fa081f38ab397c7697f9d539211b51a0cfc
Patch
https://git.kernel.org/stable/c/8356fb821016797f5677cbeee5ddc0d32a95b4be
Patch
https://git.kernel.org/stable/c/a36d990f591320e9dd379ab30063ebfe91d47e1f
Patch
https://git.kernel.org/stable/c/bf1bc673c587f5ef7e9c09b94aea7c5a7847d4d9
Patch
https://git.kernel.org/stable/c/c9b37c8b73f6368e4750e5ccb0632c380b43c6e5
Patch
https://git.kernel.org/stable/c/d582e12378bc1637f337622feef762f53c43fd57
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