{"apiVersion":"1.0","identifier":"CVE-2026-72321","description":"In the Linux kernel, the following vulnerability has been resolved: ipv4: igmp: Fix potential memory leaks in igmp_mod_timer() and igmp_stop_timer() When a timer is deleted and not re-armed in igmp_mod_timer(), or stopped in igmp_stop_timer(), the code currently decrements the reference counter of the multicast list entry @im using refcount_dec(&im->refcnt). However, both functions can be called from the RCU reader path: - igmp_mod_timer() via igmp_heard_query() -> for_each_pmc_rcu() - igmp_stop_timer() via igmp_rcv() -> igmp_heard_report() If the group im was concurrently removed from the list by ip_mc_dec_group(), its reference count might have already been decremented to 1. In this case, timer_delete() succeeds, and refcount_dec() decrements the refcount from 1 to 0. Since refcount_dec() does not free the object when it hits 0 (unlike ip_ma_put()), the im structure is leaked. Fix this by using ip_ma_put(im) instead of refcount_dec(&im->refcnt), and deferring the put until after the spinlock is released.","publishedAt":"2026-08-15T06:22:05","lastModifiedAt":"2026-08-17T06:18:35","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-72321","cvssScore":null,"cvssVector":"Pending","epssProbability":0.00207,"riskScore":0,"affectedProduct":"Linux kernel","affectedVersions":"unknown","vulnerabilityType":"Kernel","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-72321","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-72321","en":"https://www.redsauce.net/en/cves/CVE-2026-72321","fr":"https://www.redsauce.net/fr/cves/CVE-2026-72321","pt":"https://www.redsauce.net/pt/cves/CVE-2026-72321","de":"https://www.redsauce.net/de/cves/CVE-2026-72321","sk":"https://www.redsauce.net/sk/cves/CVE-2026-72321","el":"https://www.redsauce.net/el/cves/CVE-2026-72321"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-72321"}}