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