The CVSS 8.1 score on CVE-2026-68376 overstates the practical risk. This is a buffer overflow in the SCTP cookie handling code—specifically a 2-byte undersize in the auth_hmacs array calculation—but exploitation requires specific and unlikely preconditions: an endpoint must have exactly four HMAC identifiers configured, and the resulting corruption of the adjacent auth_chunks field must survive validation to trigger an out-of-bounds read in sctp_auth_get_hmac(). This isn't arbitrary kernel memory corruption; it's a bounded overwrite targeting a specific auth field with a narrow precondition chain.
What matters more than the CVSS vector is what the narrow fix reveals. The patch adjusts a single array size calculation in struct sctp_cookie. One sizeof() expression, one line. The vulnerable code path involves parameter deserialization, buffer allocation, copy operations, and field validation—multiple points where a developer must manually synchronize buffer sizing with protocol structure definitions. This class of error is a recurring genotype in kernel networking code, not a one-off mistake. The fix closes this instance but does nothing to prevent the next sizeof() miscalculation in the adjacent cookie field or the next protocol handler with similar manual size bookkeeping.
The deeper problem is that SCTP itself is forgotten code. Not deprecated—simply ignored. The protocol ships in production kernels, processes untrusted network input during association setup, and sits in a subsystem that receives minimal fuzzing, review, or active maintenance. The EPSS score of 0.00422 reflects low exploitation probability today, but it also reflects the reality that almost no one is targeting this path. The obscurity protects in the short term but creates long-term exposure debt: latent bugs accumulate without detection, and fixes for one edge case in the auth handling path may expose the next (a pattern visible in CVE-2009-0065, CVE-2019-5598, and now this). When the next sizeof() miscalculation in cookie deserialization surfaces, it will face the same patch-to-deployment lag against systems still unpatched from this one.
For defenders: verify whether your SCTP deployments use exactly four HMAC identifiers—this is the trigger condition. More importantly, treat the SCTP subsystem as a higher-risk component than its usage suggests precisely because it receives less security attention. The absence of active exploitation is a measure of attacker interest, not code quality.