Linux Kernel up to 6.6.151/6.12.103/6.18.44/7.1.8 Packet Socket TX Ring tpacket_snd hard_header_len race condition

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.
7.8$0-$5k0.86-

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.6.151/6.12.103/6.18.44/7.1.8. It has been declared as very critical. The impacted element is the function tpacket_snd of the component Packet Socket TX Ring. Executing a manipulation of the argument hard_header_len can lead to race condition. This vulnerability is handled as CVE-2026-74668. It is possible to launch the attack on the local host. There is not any exploit available.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 6.6.151/6.12.103/6.18.44/7.1.8 and classified as very critical. This vulnerability affects the function tpacket_snd of the component Packet Socket TX Ring. The manipulation of the argument hard_header_len with an unknown input leads to a race condition vulnerability. The CWE definition for the vulnerability is CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: packet: use consistent hard_header_len in TX_RING send path tpacket_snd() reads dev->hard_header_len independently for skb allocation and header construction in tpacket_fill_skb(). Concurrent netdevice reconfiguration can therefore make the reserved headroom smaller than the amount later pushed, or make copylen - hard_header_len negative. Snapshot hard_header_len once before processing ring frames and use it for the frame limit, headroom allocation, copy length, and skb construction. Pass the snapshot to tpacket_fill_skb(). The separate SOCK_DGRAM consistency problem between hard_header_len and header_ops->create is not addressed here.

The advisory is shared for download at git.kernel.org. This vulnerability was named CVE-2026-74668 since 08/15/2026. The exploitation appears to be easy. The attack needs to be approached locally. The exploitation needs additional levels of successful authentication. 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 08/22/2026).

Upgrading to version 6.6.152, 6.12.104, 6.18.45 or 7.1.9 eliminates this vulnerability. Applying the patch d85d2fd54e901637c81d847811e03c662aee13cd/016763e829cac37b3234eace86fd0a4c560de4a7/27e068d1b35dbec10a3cf268887c94407be4badc/d48ea5c9c4c34dc0df621f0e39ed3a16b644621a/21b5953e7494c16a42e6cd8cf110e18d13ae4a6b is able to eliminate this problem.

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.2
VulDB Meta Temp Score: 7.8

VulDB Base Score: 8.2
VulDB Temp Score: 7.8
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

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

Exploitinginfo

Class: Race condition
CWE: CWE-362
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

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

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.6.152/6.12.104/6.18.45/7.1.9
Patch: d85d2fd54e901637c81d847811e03c662aee13cd/016763e829cac37b3234eace86fd0a4c560de4a7/27e068d1b35dbec10a3cf268887c94407be4badc/d48ea5c9c4c34dc0df621f0e39ed3a16b644621a/21b5953e7494c16a42e6cd8cf110e18d13ae4a6b

Timelineinfo

08/15/2026 CVE reserved
08/22/2026 +7 days Advisory disclosed
08/22/2026 +0 days VulDB entry created
08/22/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-74668 (🔒)
GCVE (CVE): GCVE-0-2026-74668
GCVE (VulDB): GCVE-100-394456

Entryinfo

Created: 08/22/2026 18:49
Changes: 08/22/2026 18:49 (60)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Do you need the next level of professionalism?

Upgrade your account now!