CVE Catalog

CVE-2026-72321

Low risk· EPSS 11%
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.21%

11th percentile - higher than 11% of all known CVEs

Summary

In the Linux kernel's IPv4 IGMP module, there are potential memory leaks in igmp_mod_timer() and igmp_stop_timer() due to incorrect reference counting, leading to the multicast group structure not being freed.

Risk Assessment

Repeated multicast group operations can lead to kernel memory exhaustion.

Recommendation

Apply a Linux kernel update containing the fix that uses ip_ma_put() instead of refcount_dec() and defers the put until after the spinlock is released.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS