In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_conntrack_h323: fix OOB read in decode_choice()
In decode_choice(), the boundary check before get_len() uses the
variable `len`, which is still 0 from its initialization at the top of
the function:
unsigned int type, ext, len = 0;
...
if (ext || (son->attr & OPEN)) {
BYTE_ALIGN(bs);
if (nf_h323_error_boundary(bs, len, 0)) /* len is 0 here */
return H323_ERROR_BOUND;
len = get_len(bs); /* OOB read */
When the bitstream is exactly consumed (bs->cur == bs->end), the check
nf_h323_error_boundary(bs, 0, 0) evaluates to (bs->cur + 0 > bs->end),
which is false. The subsequent get_len() call then dereferences
*bs->cur++, reading 1 byte past the end of the buffer. If that byte
has bit 7 set, get_len() reads a second byte as well.
This can be triggered remotely by sending a crafted Q.931 SETUP message
with a User-User Information Element containing exactly 2 bytes of
PER-encoded data ({0x08, 0x00}) to port 1720 through a firewall with
the nf_conntrack_h323 helper active. The decoder fully consumes the
PER buffer before reaching this code path, resulting in a 1-2 byte
heap-buffer-overflow read confirmed by AddressSanitizer.
Fix this by checking for 2 bytes (the maximum that get_len() may read)
instead of the uninitialized `len`. This matches the pattern used at
every other get_len() call site in the same file, where the caller
checks for 2 bytes of available data before calling get_len().
References
Configurations
Configuration 1 (hide)
|
History
12 May 2026, 19:03
| Type | Values Removed | Values Added |
|---|---|---|
| CWE | CWE-125 | |
| CPE | cpe:2.3:o:linux:linux_kernel:4.15:rc7:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:4.15:rc4:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:4.15:rc9:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:4.15:rc8:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:4.15:rc6:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:4.15:rc5:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:4.15:-:*:*:*:*:*:* |
|
| First Time |
Linux linux Kernel
Linux |
|
| References | () https://git.kernel.org/stable/c/2a3aac4205e7d2f1aca2e3827de8cdd517d36c4a - Patch | |
| References | () https://git.kernel.org/stable/c/35f1943d242e1b9f0b6e91c0c93bfb293a9f8224 - Patch | |
| References | () https://git.kernel.org/stable/c/53d32735d77ab56cc3fc7bd53a7d099418f19be1 - Patch | |
| References | () https://git.kernel.org/stable/c/7ef82863d42261817a6394c6c881bd6757a70f16 - Patch | |
| References | () https://git.kernel.org/stable/c/81f2fc5b0d0cf4696146f00f837596d10b92dead - Patch | |
| References | () https://git.kernel.org/stable/c/baed0d9ba91d4f390da12d5039128ee897253d60 - Patch | |
| References | () https://git.kernel.org/stable/c/bcb50aa0b8f2b74a9fe5a1c7bee6f2657a288041 - Patch | |
| References | () https://git.kernel.org/stable/c/f0a83d0a4b7c127d32ac06d607a9214937716129 - Patch |
08 May 2026, 13:16
| Type | Values Removed | Values Added |
|---|---|---|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 8.2 |
06 May 2026, 12:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-05-06 12:16
Updated : 2026-05-12 19:03
NVD link : CVE-2026-43233
Mitre link : CVE-2026-43233
CVE.ORG link : CVE-2026-43233
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-125
Out-of-bounds Read