CVE-2026-68300
CriticalCVSS 9.8Exploitation Probability (EPSS)
Low risk10th percentile - higher than 10% of all known CVEs
Summary
In the Linux kernel SCTP subsystem, sctp_auth_chunk_verify() returns true unconditionally when chunk->auth_chunk is NULL, bypassing authentication verification. The fix checks sctp_auth_recv_cid() in such cases and drops the chunk if authentication is required.
Risk Assessment
The vulnerability may allow unauthenticated traffic to bypass SCTP authentication mechanisms, potentially leading to unauthorized access or attacks.
Recommendation
Apply the Linux kernel update containing the fix for this CVE.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: sctp: auth: verify auth requirement when auth_chunk is NULL sctp_auth_chunk_verify() returns true unconditionally when chunk->auth_chunk is NULL, silently skipping authentication. This is incorrect when: 1. skb_clone() failed in the BH receive path, leaving auth_chunk NULL. In sctp_endpoint_bh_rcv() asoc is NULL for new connections, so the early sctp_auth_recv_cid() check cannot catch this. 2. No AUTH chunk precedes COOKIE-ECHO, so skb_clone() is never called and auth_chunk remains NULL. Fix by checking sctp_auth_recv_cid() when auth_chunk is NULL: if authentication is required, return false to drop the chunk; otherwise continue normally.