Linux Kernel up to 6.18.33/7.0.10 eswitch mode net/mlx5e mlx5e_xfrm_add_state off-by-one

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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9.5$5k-$25k0.00

Summaryinfo

A vulnerability marked as very critical has been reported in Linux Kernel up to 6.18.33/7.0.10. Affected by this vulnerability is the function mlx5e_xfrm_add_state of the file net/mlx5e of the component eswitch mode. This manipulation causes off-by-one. This vulnerability is tracked as CVE-2026-64522. The attack is possible to be carried out remotely. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.18.33/7.0.10. It has been declared as very critical. Affected by this vulnerability is the function mlx5e_xfrm_add_state of the file net/mlx5e of the component eswitch mode. The manipulation with an unknown input leads to a off-by-one vulnerability. The CWE definition for the vulnerability is CWE-193. A product calculates or uses an incorrect maximum or minimum value that is 1 more, or 1 less, than the correct value. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Fix eswitch mode block underflow on IPsec acquire SA mlx5e_xfrm_add_state() handles acquire-flow temporary SAs by allocating software state and skipping hardware offload setup. That path jumps to the common success label before taking the eswitch mode block. After tunnel-mode validation was moved earlier, the common success label unconditionally calls mlx5_eswitch_unblock_mode(). For acquire SAs, this decrements esw->offloads.num_block_mode without a matching increment. Return directly after installing the acquire SA offload handle, so only the paths that successfully called mlx5_eswitch_block_mode() call the matching unblock.

The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2026-64522 since 07/19/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details are known, but no exploit is available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 07/26/2026).

Upgrading to version 6.18.34 or 7.0.11 eliminates this vulnerability. Applying the patch b5bd4249e430f5963d559708ee96a671716d2400/ecafd8284e527666e83261e6e57a7c7341d591cb/abe003b33223ff33552f291644bf35d9c2f992fb is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-48866). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.9
VulDB Meta Temp Score: 9.5

VulDB Base Score: 9.9
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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

Exploitinginfo

Class: Off-by-one
CWE: CWE-193 / CWE-189
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

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 6.18.34/7.0.11
Patch: b5bd4249e430f5963d559708ee96a671716d2400/ecafd8284e527666e83261e6e57a7c7341d591cb/abe003b33223ff33552f291644bf35d9c2f992fb

Timelineinfo

07/19/2026 CVE reserved
07/25/2026 +6 days Advisory disclosed
07/25/2026 +0 days VulDB entry created
07/26/2026 +1 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-64522 (🔒)
GCVE (CVE): GCVE-0-2026-64522
GCVE (VulDB): GCVE-100-383317
EUVD: 🔒

Entryinfo

Created: 07/25/2026 19:29
Updated: 07/26/2026 02:04
Changes: 07/25/2026 19:29 (60), 07/26/2026 02:04 (1)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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