Linux Kernel up to 6.6.151/6.12.103/6.18.44/7.1.8 packet packet_snd/packet_sendmsg_spkt out-of-bounds write

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-$25k1.48-

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 classified as very critical. The affected element is the function packet_snd/packet_sendmsg_spkt of the component packet. This manipulation causes out-of-bounds write. This vulnerability is tracked as CVE-2026-74582. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability classified as very critical was found in Linux Kernel up to 6.6.151/6.12.103/6.18.44/7.1.8. Affected by this vulnerability is the function packet_snd/packet_sendmsg_spkt of the component packet. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. The CWE definition for the vulnerability is CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. 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: packet: use consistent hard_header_len in non-ring send paths packet_snd() reads dev->hard_header_len multiple times while allocating and constructing an skb. Device reconfiguration can change this value concurrently, for example through bonding device type changes. For SOCK_RAW, packet_snd() can save a larger value in reserve and later allocate headroom using a smaller value. Moving skb->data back by reserve then places it before skb->head, and the following copy from userspace can attempt an out-of-bounds write. packet_sendmsg_spkt() has the same issue because it calculates its reservation and header offset from separate reads before dropping the RCU read lock to allocate the skb. Add LL_RESERVED_SPACE_EX() for callers that already saved a header length. Read hard_header_len once in packet_snd() and use it for allocation and construction. In packet_sendmsg_spkt(), preserve the allocation-time value through the device lookup retry. The separate SOCK_DGRAM consistency problem between hard_header_len and header_ops->create is not addressed here.

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2026-74582 since 08/15/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 08/21/2026).

Upgrading to version 6.6.152, 6.12.104, 6.18.45 or 7.1.9 eliminates this vulnerability. Applying the patch 91f041451f967cd87ed722a8f43c0b767a64f1a0/9052756290962ffb9a661bcf319e92dedaaedfed/5bb10753d428aadfc356a2bfe9acea09c82a62ec/b06b6fce6d7deaf7238e09b48ce3b1125ff41acd/03390aa32e669cc4ecd7d34108e2e1afc13d689d is able to eliminate this problem.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

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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: Out-of-bounds write
CWE: CWE-787 / 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 6.6.152/6.12.104/6.18.45/7.1.9
Patch: 91f041451f967cd87ed722a8f43c0b767a64f1a0/9052756290962ffb9a661bcf319e92dedaaedfed/5bb10753d428aadfc356a2bfe9acea09c82a62ec/b06b6fce6d7deaf7238e09b48ce3b1125ff41acd/03390aa32e669cc4ecd7d34108e2e1afc13d689d

Timelineinfo

08/15/2026 CVE reserved
08/21/2026 +6 days Advisory disclosed
08/21/2026 +0 days VulDB entry created
08/21/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-74582 (🔒)
GCVE (CVE): GCVE-0-2026-74582
GCVE (VulDB): GCVE-100-394147

Entryinfo

Created: 08/21/2026 18:59
Changes: 08/21/2026 18:59 (59)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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