{"apiVersion":"1.0","identifier":"CVE-2026-72502","description":"In the Linux kernel, the following vulnerability has been resolved: tcp: ipv6: clamp default adverting MSS to avoid GSO_BY_FRAGS (0xFFFF) When MTU is large, ip6_default_advmss() can return IPV6_MAXPLEN (65535). This is interpreted by TCP as mss_clamp, allowing the MSS to reach 65535. However, 0xFFFF is also used as a magic value GSO_BY_FRAGS in the kernel. If a TCP packet with gso_size=0xFFFF is passed to skb_segment(), it will be mistakenly treated as GSO_BY_FRAGS, leading to a NULL pointer dereference because local TCP packets do not use frag_list. Fix this by returning min(IPV6_MAXPLEN, GSO_BY_FRAGS - 1) (65534) from ip6_default_advmss() when MTU is large. Also update the stale comment in ip6_default_advmss() which suggested that IPV6_MAXPLEN is returned to mean -any MSS-.","publishedAt":"2026-08-15T06:22:24","lastModifiedAt":"2026-08-17T06:19:18","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-72502","cvssScore":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","epssProbability":0.00696,"riskScore":0.8,"affectedProduct":"Linux kernel","affectedVersions":"unknown","vulnerabilityType":"Kernel","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-72502","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-72502","en":"https://www.redsauce.net/en/cves/CVE-2026-72502","fr":"https://www.redsauce.net/fr/cves/CVE-2026-72502","pt":"https://www.redsauce.net/pt/cves/CVE-2026-72502","de":"https://www.redsauce.net/de/cves/CVE-2026-72502","sk":"https://www.redsauce.net/sk/cves/CVE-2026-72502","el":"https://www.redsauce.net/el/cves/CVE-2026-72502"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-72502"}}