{"apiVersion":"1.0","identifier":"CVE-2026-74689","description":"In the Linux kernel, the following vulnerability has been resolved: net/atm: fix slab-out-of-bounds read in vcc_setsockopt() vcc_setsockopt() contained an ineffective optlen check: if (__SO_LEVEL_MATCH(optname, level) && optlen != __SO_SIZE(optname)) return -EINVAL; If __SO_LEVEL_MATCH(optname, level) evaluated to false (e.g. if the caller passed a mismatched level), the length check optlen != __SO_SIZE(optname) was short-circuited and bypassed. Execution then fell through to switch(optname), calling copy_from_sockptr() assuming optval contained sufficient space. Furthermore, even if level matched, a cgroup BPF setsockopt filter could shrink optlen after entry. Because copy_from_sockptr() on kernel pointers uses memcpy(), this leads to a KASAN slab-out-of-bounds read when optlen is smaller than the expected structure size. Fix this by using copy_safe_from_sockptr(), which unconditionally validates that optlen is at least the expected size before copying. Also change the local -value- variable type from -unsigned long- to -int- so that SO_SETCLP matches its sizeof(int) ABI encoding on 64-bit systems.","publishedAt":"2026-08-22T16:16:43","lastModifiedAt":"2026-08-25T06:18:51","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-74689","cvssScore":7.1,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","epssProbability":0.00139,"riskScore":0.72,"affectedProduct":"Linux kernel","affectedVersions":"unknown","vulnerabilityType":"Kernel","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-74689","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-74689","en":"https://www.redsauce.net/en/cves/CVE-2026-74689","fr":"https://www.redsauce.net/fr/cves/CVE-2026-74689","pt":"https://www.redsauce.net/pt/cves/CVE-2026-74689","de":"https://www.redsauce.net/de/cves/CVE-2026-74689","sk":"https://www.redsauce.net/sk/cves/CVE-2026-74689","el":"https://www.redsauce.net/el/cves/CVE-2026-74689"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-74689"}}