The flaw lies in the handling of IPv6 hop–by–hop extensions. After a hop‑jumbo header is processed, the ipv6_hop_jumbo() function trims the buffer, which can adjust the packet’s internal pointers. Because the next‑header pointer is not recomputed, the kernel may later reference a stale value, leading to malformed packet processing and possible service disruption. The vulnerability is a classic example of pointer reuse, reflected by the associated CWE‑416, CWE‑822 and CWE‑825 identifiers.

The vulnerability affects all Linux kernel implementations that have not been patched. Vendors listed in the CVE are Linux:Linux; affected releases include kernel 2.6.12 (rc1 through rc5), kernel 7.1 (rc1 through rc5), and any kernel matching the generic CPE cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*. Systems running these kernels with IPv6 enabled are potentially at risk until the patch that recomputes the next‑header pointer is applied.

The CVSS base score of 9.8 indicates a very high level of severity, while the EPSS score of less than 1% suggests that exploitation is not yet widespread. The flaw is not listed in the CISA KEV catalog, which points to a limited current threat landscape. An attacker can trigger the issue by sending specially crafted IPv6 packets containing hop‑by‑hop extensions to a vulnerable host, and the attack vector is likely remote, relying on the victim’s network stack. The lack of public exploitation evidence reduces the immediate risk but the high severity warrants prompt remediation.