CVE-2026-64096

Analyzed Analyzed - Analysis Complete

Use-After-Free in Linux Kernel batman-adv Multicast Component

Publication date: 2026-07-19

Last updated on: 2026-08-11

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: batman-adv: mcast: fix use-after-free in orig_node RCU release batadv_mcast_purge_orig() removes entries from RCU-protected hlists but does not wait for an RCU grace period before returning. Concurrent RCU readers may still accesses references to those entries at the point of removal. RCU-protected readers trying to operate on entries like orig->mcast_want_all_ipv6_node will then access already freed memory. Fix this by moving batadv_mcast_purge_orig() to batadv_orig_node_release(), just before the call_rcu() invocation. This ensures RCU readers that were active at purge time have drained before the orig_node memory is reclaimed.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-07-19

Last Modified

2026-08-11

Generated

2026-08-29

AI Q&A

2026-07-19

EPSS Evaluated

2026-08-28

NVD

CVE-2026-64096

EUVD

EUVD-2026-45781

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	7.1
linux	linux_kernel	7.1
linux	linux_kernel	7.1
linux	linux_kernel	7.1
linux	linux_kernel	From 5.16 (inc) to 6.1.175 (exc)
linux	linux_kernel	From 5.11 (inc) to 5.15.209 (exc)
linux	linux_kernel	From 6.7 (inc) to 6.12.92 (exc)
linux	linux_kernel	From 6.13 (inc) to 6.18.34 (exc)
linux	linux_kernel	From 6.19 (inc) to 7.0.11 (exc)
linux	linux_kernel	From 6.2 (inc) to 6.6.142 (exc)
linux	linux_kernel	From 3.15 (inc) to 5.10.258 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-416	The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Attack-Flow Graph

Executive Summary

This vulnerability is a use-after-free issue in the Linux kernel's batman-adv multicast (mcast) component. It occurs when batadv_mcast_purge_orig() removes entries from RCU-protected lists without waiting for an RCU grace period. This allows concurrent RCU readers to still access freed memory, leading to potential crashes or corruption when they try to use references like orig->mcast_want_all_ipv6_node.

Detection Guidance

This vulnerability is specific to the Linux kernel's batman-adv module and involves a use-after-free issue in multicast handling. Detection requires checking kernel logs for related errors or crashes involving batman-adv, such as memory access violations or RCU warnings. Commands like dmesg | grep batman-adv or journalctl -k | grep batman-adv may help identify issues.

Impact Analysis

This vulnerability could cause system instability, crashes, or unexpected behavior in systems running affected versions of the Linux kernel with batman-adv enabled. It may lead to denial-of-service conditions if the kernel panics or corrupts memory during normal operations.

Compliance Impact

This vulnerability is a use-after-free issue in the Linux kernel's batman-adv multicast handling, which could lead to memory corruption and potential crashes. It does not directly relate to data privacy or security controls required by GDPR or HIPAA, as it is a kernel-level memory management flaw rather than a data exposure or access control issue.

Mitigation Strategies

Immediate mitigation involves updating the Linux kernel to a patched version that includes the fix for this vulnerability. Check your distribution's security updates or kernel patches for CVE-2026-64096. If updating is not immediately possible, consider disabling the batman-adv module if multicast functionality is not required.

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