Critical severity · published Apr 24, 2026
CVE-2026-31636
rxrpc: fix RESPONSE authenticator parser OOB read
9.1
CVSS
0.4%
EPSS
No
On KEV
Description
In the Linux kernel, the following vulnerability has been resolved:
rxrpc: fix RESPONSE authenticator parser OOB read
rxgk_verify_authenticator() copies auth_len bytes into a temporary
buffer and then passes p + auth_len as the parser limit to
rxgk_do_verify_authenticator(). Since p is a __be32 *, that inflates the
parser end pointer by a factor of four and lets malformed RESPONSE
authenticators read past the kmalloc() buffer.
Decoded from the original latest-net reproduction logs with
scripts/decode_stacktrace.sh:
BUG: KASAN: slab-out-of-bounds in rxgk_verify_response()
Call Trace:
dump_stack_lvl() [lib/dump_stack.c:123]
print_report() [mm/kasan/report.c:379 mm/kasan/report.c:482]
kasan_report() [mm/kasan/report.c:597]
rxgk_verify_response()
[net/rxrpc/rxgk.c:1103 net/rxrpc/rxgk.c:1167
net/rxrpc/rxgk.c:1274]
rxrpc_process_connection()
[net/rxrpc/conn_event.c:266 net/rxrpc/conn_event.c:364
net/rxrpc/conn_event.c:386]
process_one_work() [kernel/workqueue.c:3281]
worker_thread()
[kernel/workqueue.c:3353 kernel/workqueue.c:3440]
kthread() [kernel/kthread.c:436]
ret_from_fork() [arch/x86/kernel/process.c:164]
Allocated by task 54:
rxgk_verify_response()
[include/linux/slab.h:954 net/rxrpc/rxgk.c:1155
net/rxrpc/rxgk.c:1274]
rxrpc_process_connection()
[net/rxrpc/conn_event.c:266 net/rxrpc/conn_event.c:364
net/rxrpc/conn_event.c:386]
Convert the byte count to __be32 units before constructing the parser
limit.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 38% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KE
Kernel · Linux
6.16.1 before 6.18.23; 6.19 before 6.19.13; 6.16; 7.0; 7.0; 7.0; +4 more · source: NVD
LI
Linux · Linux
9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a before 7875f3d9777bd4e9892c4db830571ab8ac2044c0; 9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a before 20a188775a9a9982d1987e12660d9b44b40a6c99; 9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a before 3e3138007887504ee9206d0bfb5acb062c600025; 6.16 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-31636
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-31636
Patch
https://git.kernel.org/stable/c/20a188775a9a9982d1987e12660d9b44b40a6c99
Patch
https://git.kernel.org/stable/c/3e3138007887504ee9206d0bfb5acb062c600025
Patch
https://git.kernel.org/stable/c/7875f3d9777bd4e9892c4db830571ab8ac2044c0
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