Linux Kernel up to 6.18.39/7.1.4 rxrpc rxrpc_receiving_reply/rxrpc_rotate_tx_window input validation

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.2	$0-$5k	0.00

Summaryinfo

A vulnerability described as critical has been identified in Linux Kernel up to 6.18.39/7.1.4. This impacts the function rxrpc_receiving_reply/rxrpc_rotate_tx_window of the component rxrpc. Executing a manipulation can lead to input validation. This vulnerability appears as CVE-2026-74429. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 6.18.39/7.1.4 and classified as critical. This vulnerability affects the function rxrpc_receiving_reply/rxrpc_rotate_tx_window of the component rxrpc. The manipulation with an unknown input leads to a input validation vulnerability. The CWE definition for the vulnerability is CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. As an impact it is known to affect availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix the reception of a reply packet before data transmission Fix rxrpc_receiving_reply() to handle the reception of an apparent reply DATA packet before rxrpc has had a chance to send any request DATA packets on a client call by checking to see if the call has been exposed yet by sending the first packet. Without this, rxrpc_rotate_tx_window() might oops. Also fix rxrpc_rotate_tx_window() to handle the Tx queue being empty by changing the do...while loop into a while loop, just in case a call is abnormally terminated by an early reply before the last request packet is transmitted.

The advisory is shared for download at git.kernel.org. This vulnerability was named CVE-2026-74429 since 08/15/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 08/15/2026).

Upgrading to version 6.18.40, 7.1.5 or 7.2-rc1 eliminates this vulnerability. Applying the patch f9be514984471ff0003738b2e1efed12bc3433ff/e220ae559e5a0fc33e41ec6a348ea50387cb8b0f/a58e33405acd2584e730c1da72635f822ada6b49 is able to eliminate this problem.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9
• 6.18.10
• 6.18.11
• 6.18.12
• 6.18.13
• 6.18.14
• 6.18.15
• 6.18.16
• 6.18.17
• 6.18.18
• 6.18.19
• 6.18.20
• 6.18.21
• 6.18.22
• 6.18.23
• 6.18.24
• 6.18.25
• 6.18.26
• 6.18.27
• 6.18.28
• 6.18.29
• 6.18.30
• 6.18.31
• 6.18.32
• 6.18.33
• 6.18.34
• 6.18.35
• 6.18.36
• 6.18.37
• 6.18.38
• 6.18.39
• 7.1.0
• 7.1.1
• 7.1.2
• 7.1.3
• 7.1.4

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.5
VulDB Meta Temp Score: 7.2

VulDB Base Score: 7.5
VulDB Temp Score: 7.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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

Exploitinginfo

Class: Input validation
CWE: CWE-20
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

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

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.18.40/7.1.5/7.2-rc1
Patch: f9be514984471ff0003738b2e1efed12bc3433ff/e220ae559e5a0fc33e41ec6a348ea50387cb8b0f/a58e33405acd2584e730c1da72635f822ada6b49

Timelineinfo

08/15/2026 Advisory disclosed
08/15/2026 +0 days CVE reserved
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-2026-74429 (🔒)
GCVE (CVE): GCVE-0-2026-74429
GCVE (VulDB): GCVE-100-390388

Entryinfo

Created: 08/15/2026 10:45
Changes: 08/15/2026 10:45 (59)
Complete: 🔍
Cache ID: 216::103

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