High severity · published May 1, 2026
CVE-2026-31694
fuse: reject oversized dirents in page cache
7.8
CVSS
0.3%
EPSS
No
On KEV
Description
In the Linux kernel, the following vulnerability has been resolved:
fuse: reject oversized dirents in page cache
fuse_add_dirent_to_cache() computes a serialized dirent size from the
server-controlled namelen field and copies the dirent into a single
page-cache page. The existing logic only checks whether the dirent fits
in the remaining space of the current page and advances to a fresh page
if not. It never checks whether the dirent itself exceeds PAGE_SIZE.
As a result, a malicious FUSE server can return a dirent with
namelen=4095, producing a serialized record size of 4120 bytes. On 4 KiB
page systems this causes memcpy() to overflow the cache page by 24 bytes
into the following kernel page.
Reject dirents that cannot fit in a single page before copying them into
the readdir cache.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 21% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KE
Kernel · Linux
6.15 before 6.18.25; 6.19 before 7.0.2; 7.1; 7.1 · source: NVD
LI
Linux · Linux
27992ef80770d61a57f6c3a551735b08cefdffa3 before 7de93abfaae1b2dc94da8a07a36421bd073f1d8f; 27992ef80770d61a57f6c3a551735b08cefdffa3 before 474ce83c96a55f2eeb14dee2be375eeadfdacdf5; 27992ef80770d61a57f6c3a551735b08cefdffa3 before 51a8de6c50bf947c8f534cd73da4c8f0a13e7bed; 6.15 · source: vendor
SS
Simatic S7-1500 TM Mfp Firmware · Siemens
All versions, or not specified · source: NVD
SS
SIMATIC S7-1500 TM MFP - GNU/Linux subsystem · Siemens
0 · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-31694
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-31694
Patch
https://git.kernel.org/stable/c/474ce83c96a55f2eeb14dee2be375eeadfdacdf5
Patch
https://git.kernel.org/stable/c/51a8de6c50bf947c8f534cd73da4c8f0a13e7bed
Patch
https://git.kernel.org/stable/c/7de93abfaae1b2dc94da8a07a36421bd073f1d8f
Third Party Advisory
https://cert-portal.siemens.com/productcert/html/ssa-784472.html
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