Critical severity · published Sep 11, 2026
CVE-2026-89526
svcrdma: Validate Read chunk positions before reconstruction
9.8
CVSS
0.6%
EPSS
No
On KEV
Description
In the Linux kernel, the following vulnerability has been resolved:
svcrdma: Validate Read chunk positions before reconstruction
The RPC/RDMA Read chunk position field is supplied by the remote
client and stored verbatim in the parsed chunk list.
xdr_count_read_segments() checks only 4-byte alignment; it never
compares the position against the received inline body length.
In the single-chunk path, svc_rdma_read_complete_one() splits the
head and tail kvecs at ch_position. A position past the inline
body underflows the tail length, exposing adjacent slab memory to
the upper XDR decoder.
In the multi-chunk path, svc_rdma_read_multiple_chunks() computes
gap lengths between chunks as unsigned subtractions from
ch_position. Overlapping Read chunks cause these subtractions to
underflow. A final position past the inline body likewise
underflows the trailing gap length. svc_rdma_copy_inline_range()
then copies past the receive buffer into request pages that are
returned to the client through the Reply channel.
Bound inline-range copies in svc_rdma_copy_inline_range() against
the decoded inline RPC body saved in rc_saved_arg. Reject a
single Read chunk positioned beyond that body, and reject
multi-chunk lists where accumulated read bytes exceed the next
chunk's position. Apply the same position and overlap checks in
the call-chunk interleaving path.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 50% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
Linux · Linux
d96962e6d0e281bab6a48e83b42f5dce6eb28bf4 before 3861eeabaebe243050952b34063763527c44e1fe; d96962e6d0e281bab6a48e83b42f5dce6eb28bf4 before 5ab3f6d882fe07ae5e61d0bcfeea00b9409155c2; d96962e6d0e281bab6a48e83b42f5dce6eb28bf4 before f84ec84d8d4bc65f9ae23372570349687f66fa39; d96962e6d0e281bab6a48e83b42f5dce6eb28bf4 before 577097455d084610fc31e91e6a61c5793b6f04ba; d96962e6d0e281bab6a48e83b42f5dce6eb28bf4 before 3779b7b9e7d1c8ba4738f9d327de3b0288cefe9b; 5.11 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-89526
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-89526
git.kernel.org
https://git.kernel.org/stable/c/3779b7b9e7d1c8ba4738f9d327de3b0288cefe9b
git.kernel.org
https://git.kernel.org/stable/c/3861eeabaebe243050952b34063763527c44e1fe
git.kernel.org
https://git.kernel.org/stable/c/577097455d084610fc31e91e6a61c5793b6f04ba
git.kernel.org
https://git.kernel.org/stable/c/5ab3f6d882fe07ae5e61d0bcfeea00b9409155c2
git.kernel.org
https://git.kernel.org/stable/c/f84ec84d8d4bc65f9ae23372570349687f66fa39
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