CVE-2026-53212

netfilter: nft_tunnel: fix use-after-free on object destroy

State: Published
Severity: 7.8 High
Published: Jun 25, 2026
Updated: Oct 19, 2026
Reserved: Jun 9, 2026

Description

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nft_tunnel: fix use-after-free on object destroy

nft_tunnel_obj_destroy() calls metadata_dst_free() which directly kfree()s the metadata_dst, ignoring the dst_entry refcount. Packets that took a reference via dst_hold() in nft_tunnel_obj_eval() and are still queued (e.g. in a netem qdisc) are left with a dangling pointer. When these packets are eventually dequeued, dst_release() operates on freed memory.

Replace metadata_dst_free() with dst_release() so the metadata_dst is freed only after all references are dropped. The dst subsystem already handles metadata_dst cleanup in dst_destroy() when DST_METADATA is set.

Scores

CVSS	Score	Vector	Source
3.1	7.8 High	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	Linux

Weaknesses

CWE-416 Use After Free

Affected Products

Product	Versions
LinuxLinux	af308b94a2a4a5a27bec9028354c4df444a7c8ba to before 349df61526d2e39decc685d246202e3e284cfe05Affected af308b94a2a4a5a27bec9028354c4df444a7c8ba to before 55b79b1ae42372012413ce0413181d26679b17efAffected af308b94a2a4a5a27bec9028354c4df444a7c8ba to before 5e9ee18b27fde88cb6148202b33916c66693fe82Affected af308b94a2a4a5a27bec9028354c4df444a7c8ba to before 8767fe4079affa74314d7eb3220e700150289842Affected af308b94a2a4a5a27bec9028354c4df444a7c8ba to before fda6573a46ad24f35348e024905ee5bdf729797eAffected af308b94a2a4a5a27bec9028354c4df444a7c8ba to before 941d7394efda5e054e2d6f3e0dd0f6a9ba19aaa3Affected af308b94a2a4a5a27bec9028354c4df444a7c8ba to before f9a0e4b61054cde89a2a77845293c726cc07cc43Affected af308b94a2a4a5a27bec9028354c4df444a7c8ba to before c32b26aaa2f9216520a38b3f4bfeec846eb3eb8aAffected
LinuxLinux	4.19Affected before 4.19Not affected 5.10.259 through 5.10.Not affected 5.15.210 through 5.15.Not affected 6.1.176 through 6.1.Not affected 6.6.143 through 6.6.Not affected 6.12.94 through 6.12.Not affected 6.18.36 through 6.18.Not affected 7.0.13 through 7.0.*Not affected 7.1 and laterNot affected

Product

Versions

LinuxLinux

af308b94a2a4a5a27bec9028354c4df444a7c8ba to before 349df61526d2e39decc685d246202e3e284cfe05Affected
af308b94a2a4a5a27bec9028354c4df444a7c8ba to before 55b79b1ae42372012413ce0413181d26679b17efAffected
af308b94a2a4a5a27bec9028354c4df444a7c8ba to before 5e9ee18b27fde88cb6148202b33916c66693fe82Affected
af308b94a2a4a5a27bec9028354c4df444a7c8ba to before 8767fe4079affa74314d7eb3220e700150289842Affected
af308b94a2a4a5a27bec9028354c4df444a7c8ba to before fda6573a46ad24f35348e024905ee5bdf729797eAffected
af308b94a2a4a5a27bec9028354c4df444a7c8ba to before 941d7394efda5e054e2d6f3e0dd0f6a9ba19aaa3Affected
af308b94a2a4a5a27bec9028354c4df444a7c8ba to before f9a0e4b61054cde89a2a77845293c726cc07cc43Affected
af308b94a2a4a5a27bec9028354c4df444a7c8ba to before c32b26aaa2f9216520a38b3f4bfeec846eb3eb8aAffected

LinuxLinux

4.19Affected
before 4.19Not affected
5.10.259 through 5.10.*Not affected
5.15.210 through 5.15.*Not affected
6.1.176 through 6.1.*Not affected
6.6.143 through 6.6.*Not affected
6.12.94 through 6.12.*Not affected
6.18.36 through 6.18.*Not affected
7.0.13 through 7.0.*Not affected
7.1 and laterNot affected

References

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