In the Linux kernel, the following vulnerability has been resolved:
rxrpc: Fix missing validation of ticket length in non-XDR key preparsing
In rxrpc_preparse(), there are two paths for parsing key payloads: the
XDR path (for large payloads) and the non-XDR path (for payloads <= 28
bytes). While the XDR path (rxrpc_preparse_xdr_rxkad()) correctly
validates the ticket length against AFSTOKEN_RK_TIX_MAX, the non-XDR
path fails to do so.
This allows an unprivileged user to provide a very large ticket length.
When this key is later read via rxrpc_read(), the total
token size (toksize) calculation results in a value that exceeds
AFSTOKEN_LENGTH_MAX, triggering a WARN_ON().
[ 2001.302904] WARNING: CPU: 2 PID: 2108 at net/rxrpc/key.c:778 rxrpc_read+0x109/0x5c0 [rxrpc]
Fix this by adding a check in the non-XDR parsing path of rxrpc_preparse()
to ensure the ticket length does not exceed AFSTOKEN_RK_TIX_MAX,
bringing it into parity with the XDR parsing logic.
References
Configurations
Configuration 1 (hide)
|
History
01 Jun 2026, 17:16
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
06 May 2026, 19:17
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://git.kernel.org/stable/c/1fa36cf495b0023e8475d038535c05e4063211e1 - Patch | |
| References | () https://git.kernel.org/stable/c/4458757c020592a3094366e0fb20457383b42f92 - Patch | |
| References | () https://git.kernel.org/stable/c/a1be1c9ece26cea69654f28b255ff9a7906b897b - Patch | |
| References | () https://git.kernel.org/stable/c/ac33733b10b484d666f97688561670afd5861383 - Patch | |
| References | () https://git.kernel.org/stable/c/ce383ba615339f8eaec646a166d2c2b015bb5ca0 - Patch | |
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 7.8 |
| First Time |
Linux
Linux linux Kernel |
|
| CWE | CWE-787 | |
| CPE | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* |
01 May 2026, 14:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-05-01 14:16
Updated : 2026-06-01 17:16
NVD link : CVE-2026-31696
Mitre link : CVE-2026-31696
CVE.ORG link : CVE-2026-31696
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-787
Out-of-bounds Write