Linux Kernel up to 7.2-rc1 macsec net/mlx5e macsec_del_rxsc_ctx use after free

CVSS Meta Temp Score
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CTI Interest Score
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9.5$5k-$25k0.95

Summaryinfo

A vulnerability described as very critical has been identified in Linux Kernel up to 7.2-rc1. This affects the function macsec_del_rxsc_ctx of the file net/mlx5e of the component macsec. The manipulation results in use after free. This vulnerability is identified as CVE-2026-72072. The attack can be executed remotely. There is not any exploit available.

Detailsinfo

A vulnerability, which was classified as very critical, was found in Linux Kernel up to 7.2-rc1. Affected is the function macsec_del_rxsc_ctx of the file net/mlx5e of the component macsec. The manipulation with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: macsec: fix use-after-free of metadata_dst on RX SC delete When an offloaded MACsec RX SC is deleted, macsec_del_rxsc_ctx() freed the per-SC metadata_dst with metadata_dst_free(), which kfree()s the object unconditionally and ignores the dst reference count. The RX datapath in mlx5e_macsec_offload_handle_rx_skb() looks up the SC under rcu_read_lock() via xa_load(), takes a reference with dst_hold() and attaches the dst to the skb with skb_dst_set(). A reader that already obtained the rx_sc pointer can race with the delete path and operate on freed memory. Fix the owner side by dropping the reference with dst_release() instead of freeing unconditionally, and convert the RX datapath to dst_hold_safe() so a reader racing the SC delete cannot attach a dst whose last reference was just dropped; only attach it when a reference was actually taken. mlx5e_macsec_add_rxsc() also published sc_xarray_element via xa_alloc() before rx_sc->md_dst was allocated and initialised, so a datapath reader that looked the SC up by fs_id could observe rx_sc with md_dst still NULL or, on weakly-ordered architectures, a non-NULL md_dst pointer whose contents were not yet visible. NULL-check the xa_load() result and md_dst on the datapath, and reorder add_rxsc() so the xa_alloc() publish happens only after md_dst is fully initialised; the xarray RCU publish then pairs with the rcu_read_lock()/xa_load() in the datapath. Note: macsec_del_rxsc_ctx() also kfree()s rx_sc->sc_xarray_element without an RCU grace period while the same datapath reads it under rcu_read_lock(); that is a separate pre-existing issue left to a follow-up patch. Found by 0sec automated security-research tooling (https://0sec.ai).

The advisory is available at git.kernel.org. This vulnerability is traded as CVE-2026-72072 since 08/09/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 08/15/2026).

Upgrading to version 6.1.178, 6.6.145, 6.12.97, 6.18.40, 7.1.5 or 7.2-rc2 eliminates this vulnerability. Applying the patch b1a4d0c568bbb52c7c04f4fce3c097dae89ed6cb/218cc15a4c907659ad4b0e68c535c61594311205/4a5073b7b30243658f58b2d2d35a823da7fd34d9/ed3cc4218070d6b98bf5fb456dccae424fd38c4f/088873af13590ebde10de2ade847f57a05ec61c6/de74d8fd10291763d97b218f09adcc7513c975e4 is able to eliminate this problem.

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Productinfo

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Version

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 10.0
VulDB Meta Temp Score: 9.5

VulDB Base Score: 10.0
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.1.178/6.6.145/6.12.97/6.18.40/7.1.5/7.2-rc2
Patch: b1a4d0c568bbb52c7c04f4fce3c097dae89ed6cb/218cc15a4c907659ad4b0e68c535c61594311205/4a5073b7b30243658f58b2d2d35a823da7fd34d9/ed3cc4218070d6b98bf5fb456dccae424fd38c4f/088873af13590ebde10de2ade847f57a05ec61c6/de74d8fd10291763d97b218f09adcc7513c975e4

Timelineinfo

08/09/2026 CVE reserved
08/15/2026 +6 days Advisory disclosed
08/15/2026 +0 days VulDB entry created
08/15/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-72072 (🔒)
GCVE (CVE): GCVE-0-2026-72072
GCVE (VulDB): GCVE-100-390486

Entryinfo

Created: 08/15/2026 11:50
Changes: 08/15/2026 11:50 (60)
Complete: 🔍
Cache ID: 216::103

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