CVE-2026-53212
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.15%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.15% probability · 5th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-416
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/349df61526d2e39decc685d246202e3e284cfe05Patch
- https://git.kernel.org/stable/c/55b79b1ae42372012413ce0413181d26679b17efPatch
- https://git.kernel.org/stable/c/5e9ee18b27fde88cb6148202b33916c66693fe82Patch
- https://git.kernel.org/stable/c/8767fe4079affa74314d7eb3220e700150289842Patch
- https://git.kernel.org/stable/c/941d7394efda5e054e2d6f3e0dd0f6a9ba19aaa3Patch
- https://git.kernel.org/stable/c/c32b26aaa2f9216520a38b3f4bfeec846eb3eb8aPatch
- https://git.kernel.org/stable/c/f9a0e4b61054cde89a2a77845293c726cc07cc43Patch
- https://git.kernel.org/stable/c/fda6573a46ad24f35348e024905ee5bdf729797ePatch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.