In the Linux kernel, the following vulnerability has been resolved:
sctp: fix soft lockup from unpadded ASCONF-ACK parameter iteration
sctp_verify_asconf() walks ASCONF-ACK parameters with
sctp_walk_params(), which advances by SCTP_PAD4(length), while the
consumer sctp_get_asconf_response() iterates the same parameters
advancing by the raw length, without padding. A single odd-length
parameter desynchronises the two walks and makes the consumer
interpret attacker-controlled bytes at a misaligned offset.
When those bytes yield a length of zero, the while loop over
asconf_ack_len makes no progress, spinning forever in softirq
context, and the watchdog reports a soft lockup. All reads stay
within the received skb, so the lockup is a pure remote denial of
service. A remote peer can trigger it with a crafted ASCONF-ACK on
an ADD-IP enabled association with an outstanding ASCONF (RFC 5061
section 4.1.2 requires the chunk to be authenticated, but the
predefined empty key id 0 allows the peer to compute the same
association HMAC from publicly exchanged parameters, so the gate
does not help).
The SCTP_PARAM_ERR_CAUSE case of sctp_verify_asconf() also performs
no length check, letting a parameter without a complete error
header reach the consumer, which reads errhdr.cause past the end of
the parameter, an out-of-bounds read.
Reject SCTP_PARAM_ERR_CAUSE parameters shorter than
sizeof(struct sctp_addip_param) + sizeof(struct sctp_errhdr) at the
verifier, and advance the consumer iterator with the same padding
rule as the verifier to keep the two walks in lockstep. The verifier
change guarantees a complete error header in every ERR_CAUSE
parameter the consumer can see, so the consumer's asconf_ack_len
check is dropped and it returns err_param->cause directly. The
consumer padding fix is still required because odd lengths remain
valid for SCTP_PARAM_ERR_CAUSE per RFC 5061.
The issue was found by ZeroHive, a vulnerability hunting agent at
Tencent Yunding Lab.
References
Configurations
Configuration 1 (hide)
|
History
22 Oct 2026, 16:46
| Type | Values Removed | Values Added |
|---|---|---|
| CPE | cpe:2.3:o:linux:linux_kernel:2.6.12:-:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:2.6.12:rc4:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:2.6.12:rc3:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:2.6.12:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:2.6.12:rc5:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.3:rc1:*:*:*:*:*:* |
|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.5 |
| References | () https://git.kernel.org/stable/c/2cb0b0b1ed69430bf73740377ea0a1c44c50db63 - Patch | |
| References | () https://git.kernel.org/stable/c/3be02999ab9131a4b96eb1eda4ca48b1cea80f03 - Patch | |
| References | () https://git.kernel.org/stable/c/4548d843e7b29f6d150d8caae4e64015fa226b0c - Patch | |
| References | () https://git.kernel.org/stable/c/5fbc6a778d5fce7628821236972596acb18e1065 - Patch | |
| References | () https://git.kernel.org/stable/c/7ba84e2971d208a2d6413a334ec28a8a32cdce0f - Patch | |
| References | () https://git.kernel.org/stable/c/7d8e7ab6a0665888beee91f7ad77ac805963c4fd - Patch | |
| References | () https://git.kernel.org/stable/c/abf59d7f6fff23227256e8199aca5ade45758f8b - Patch | |
| References | () https://git.kernel.org/stable/c/ba54cad229977f4fae6355dbdaf117088414fdd0 - Patch | |
| CWE | CWE-667 | |
| First Time |
Linux linux Kernel
Linux |
03 Oct 2026, 11:18
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
25 Sep 2026, 11:17
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-09-25 11:17
Updated : 2026-10-22 16:46
NVD link : CVE-2026-98123
Mitre link : CVE-2026-98123
CVE.ORG link : CVE-2026-98123
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-667
Improper Locking