SEPTEMBER 19, 2026
Live Feed
Back to database
Case File

CVE-2026-72021

HIGH · CVSS 8.2 EPSS 0.59%

Source: NVD + CISA KEV + EPSS · Published 2026-08-15 · Last synced 2026-09-14

CyberRota Analysis

AI-Generated

The vulnerability affects the Linux kernel's IP Virtual Server (IPVS) implementation, specifically in the handling of SCTP (Stream Control Transmission Protocol) state transitions for IPv6 packets with extension headers. An attacker could exploit this flaw to incorrectly manipulate the state machine, causing a connection to transition to an established state prematurely, which could lead to improper resource allocation and potential denial of service. Organizations using Linux servers with IPVS for SCTP traffic should prioritize patching this vulnerability to ensure the integrity and reliability of their network connections.

CVE
CVE-2026-72021
Severity
HIGH
CVSS
8.2
EPSS
0.59%
Linux

Original NVD Description

In the Linux kernel, the following vulnerability has been resolved: ipvs: use parsed transport offset in SCTP state lookup set_sctp_state() reads the SCTP chunk header again in order to drive the IPVS SCTP state table. For IPv6 it computes the offset with sizeof(struct ipv6hdr), while the surrounding IPVS code uses iph.len from ip_vs_fill_iph_skb(), where ipv6_find_hdr() has already skipped extension headers and found the real transport header. This makes the state machine read from the wrong offset for IPv6 SCTP packets that carry extension headers. For example, an INIT packet with an 8-byte destination options header can be scheduled correctly by sctp_conn_schedule(), but set_sctp_state() reads the first byte of the SCTP verification tag as a DATA chunk type. The connection then moves from NONE to ESTABLISHED instead of INIT1, gets the longer established timeout, and updates the active/inactive destination counters incorrectly. This happens even though the SCTP handshake has not completed. Use the parsed transport offset passed down from ip_vs_set_state() for the SCTP chunk-header lookup. For IPv4 and IPv6 packets without extension headers this preserves the existing offset.