CVE-2026-53212
netfilter: nft_tunnel: fix use-after-free on object destroy
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.
INFO
Published Date :
June 25, 2026, 9:16 a.m.
Last Modified :
July 2, 2026, 8:53 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
- Replace metadata_dst_free with dst_release.
- Ensure dst subsystem handles metadata_dst cleanup.
- Update the Linux kernel to the latest version.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-53212.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-53212 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-53212
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-53212 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-53212 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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Initial Analysis by [email protected]
Jul. 02, 2026
Action Type Old Value New Value Added CWE CWE-416 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.16 up to (excluding) 6.1.176 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.143 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.15.210 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.19 up to (excluding) 5.10.259 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.18.36 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.94 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 7.0.13 *cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc6:*:*:*:*:*:* Added Reference Type kernel.org: https://git.kernel.org/stable/c/349df61526d2e39decc685d246202e3e284cfe05 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/55b79b1ae42372012413ce0413181d26679b17ef Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/5e9ee18b27fde88cb6148202b33916c66693fe82 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/8767fe4079affa74314d7eb3220e700150289842 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/941d7394efda5e054e2d6f3e0dd0f6a9ba19aaa3 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/c32b26aaa2f9216520a38b3f4bfeec846eb3eb8a Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/f9a0e4b61054cde89a2a77845293c726cc07cc43 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/fda6573a46ad24f35348e024905ee5bdf729797e Types: Patch -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jun. 28, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jun. 25, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'af308b94a2a4a5a27bec9028354c4df444a7c8ba', 'lessThan': '349df61526d2e39decc685d246202e3e284cfe05', 'versionType': 'git'}, {'status': 'affected', 'version': 'af308b94a2a4a5a27bec9028354c4df444a7c8ba', 'lessThan': '55b79b1ae42372012413ce0413181d26679b17ef', 'versionType': 'git'}, {'status': 'affected', 'version': 'af308b94a2a4a5a27bec9028354c4df444a7c8ba', 'lessThan': '5e9ee18b27fde88cb6148202b33916c66693fe82', 'versionType': 'git'}, {'status': 'affected', 'version': 'af308b94a2a4a5a27bec9028354c4df444a7c8ba', 'lessThan': '8767fe4079affa74314d7eb3220e700150289842', 'versionType': 'git'}, {'status': 'affected', 'version': 'af308b94a2a4a5a27bec9028354c4df444a7c8ba', 'lessThan': 'fda6573a46ad24f35348e024905ee5bdf729797e', 'versionType': 'git'}, {'status': 'affected', 'version': 'af308b94a2a4a5a27bec9028354c4df444a7c8ba', 'lessThan': '941d7394efda5e054e2d6f3e0dd0f6a9ba19aaa3', 'versionType': 'git'}, {'status': 'affected', 'version': 'af308b94a2a4a5a27bec9028354c4df444a7c8ba', 'lessThan': 'f9a0e4b61054cde89a2a77845293c726cc07cc43', 'versionType': 'git'}, {'status': 'affected', 'version': 'af308b94a2a4a5a27bec9028354c4df444a7c8ba', 'lessThan': 'c32b26aaa2f9216520a38b3f4bfeec846eb3eb8a', 'versionType': 'git'}], 'programFiles': ['net/netfilter/nft_tunnel.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '4.19'}, {'status': 'unaffected', 'version': '0', 'lessThan': '4.19', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.10.259', 'versionType': 'semver', 'lessThanOrEqual': '5.10.*'}, {'status': 'unaffected', 'version': '5.15.210', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.176', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.143', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.94', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.36', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.0.13', 'versionType': 'semver', 'lessThanOrEqual': '7.0.*'}, {'status': 'unaffected', 'version': '7.1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/netfilter/nft_tunnel.c'], 'defaultStatus': 'affected'}] Added 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. Added Reference https://git.kernel.org/stable/c/349df61526d2e39decc685d246202e3e284cfe05 Added Reference https://git.kernel.org/stable/c/55b79b1ae42372012413ce0413181d26679b17ef Added Reference https://git.kernel.org/stable/c/5e9ee18b27fde88cb6148202b33916c66693fe82 Added Reference https://git.kernel.org/stable/c/8767fe4079affa74314d7eb3220e700150289842 Added Reference https://git.kernel.org/stable/c/941d7394efda5e054e2d6f3e0dd0f6a9ba19aaa3 Added Reference https://git.kernel.org/stable/c/c32b26aaa2f9216520a38b3f4bfeec846eb3eb8a Added Reference https://git.kernel.org/stable/c/f9a0e4b61054cde89a2a77845293c726cc07cc43 Added Reference https://git.kernel.org/stable/c/fda6573a46ad24f35348e024905ee5bdf729797e