CVE intelligence

CVE-2026-31636

Vulnerability intelligence

Published Apr 24, 2026Sources checked Oct 28, 2026

9.1CRITICALCVSS out of 10

What this means

Review the available evidence

CVE-2026-31636 and is rated Critical severity with a CVSS score of 9.1. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Ubuntu Security Notices guidance

Vendor revision: Aug 18, 2026

Vendor remediation details

This update corrects flaws in the following subsystems: - x86 architecture; - InfiniBand drivers; - Media drivers; - Network drivers; - Mellanox network drivers; - Texas Instruments network drivers; - NVME drivers; - File systems infrastructure; - SMB network file system; - IPv4 networking; - Network traffic control; - TCP network protocol; - Locking primitives; - Memory management; - IPv6 networking; - Multipath TCP; - Netfilter; - RxRPC session sockets; - SCTP protocol; - SMC sockets; (CVE-2026-31405, CVE-2026-31414, CVE-2026-31501, CVE-2026-31589, CVE-2026-31633, CVE-2026-31636, CVE-2026-31705, CVE-2026-43198, CVE-2026-43379, CVE-2026-43465, CVE-2026-43499, CVE-2026-46113, CVE-2026-46137, CVE-2026-46242, CVE-2026-46331, CVE-2026-52924, CVE-2026-52989, CVE-2026-53086, CVE-2026-53131, CVE

CISA KEVNot listedBased on the latest collected catalog

EPSS0.4%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-31636?

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.

Source: NVD