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-$25k1.60

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.

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 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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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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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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