Linux Kernel up to 7.1.8 UDP Tunnel Segmentation __skb_udp_tunnel_segment use after free

CVSS Meta Temp Score
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CTI Interest Score
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9.5$5k-$25k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 7.1.8 and classified as very critical. This vulnerability affects the function __skb_udp_tunnel_segment of the component UDP Tunnel Segmentation. Such manipulation leads to use after free. This vulnerability is documented as CVE-2026-74705. The attack can be executed remotely. There is not any exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 7.1.8. It has been rated as very critical. Affected by this issue is the function __skb_udp_tunnel_segment of the component UDP Tunnel Segmentation. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: udp: fix potential use-after-free in tunnel segmentation __skb_udp_tunnel_segment() gets the UDP header before ensuring the tunnel header is in the skb head. If the pull reallocates skb->head, the saved UDP header pointer is no longer valid. Get the UDP header after the pull to avoid a potential use-after-free.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2026-74705 since 08/15/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 08/23/2026).

The vulnerability scanner Nessus provides a plugin with the ID 339024 (Linux Distros Unpatched Vulnerability : CVE-2026-74705), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.10.265, 5.15.216, 6.1.183, 6.6.152, 6.12.104, 6.18.45 or 7.1.9 eliminates this vulnerability. Applying the patch 6a733a38b983d8c2e222f13968209010cf44de87/19d89b13a43640b2da2f277ee462d919d988cb6f/b3df61bb745eb5201eac22679a2839d4ccbf3442/1ae134c012e10384cdac420b5cc6e0615cde0b55/5161e67c561c4f28a5d9335a6e859b02511de92b/64d322c288577793eedd352b96ef75234ed380fe/588d4a6795d99d080f74ef0b5f391ea8c453ae5d/d0f86fb36eb260abd10007b62c9dcc1028e03e61 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 Tenable (339024). VulDB is the best source for vulnerability data and more expert information about this specific topic.

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: Use after free
CWE: CWE-416 / CWE-119
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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Nessus ID: 339024
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-74705

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.265/5.15.216/6.1.183/6.6.152/6.12.104/6.18.45/7.1.9
Patch: 6a733a38b983d8c2e222f13968209010cf44de87/19d89b13a43640b2da2f277ee462d919d988cb6f/b3df61bb745eb5201eac22679a2839d4ccbf3442/1ae134c012e10384cdac420b5cc6e0615cde0b55/5161e67c561c4f28a5d9335a6e859b02511de92b/64d322c288577793eedd352b96ef75234ed380fe/588d4a6795d99d080f74ef0b5f391ea8c453ae5d/d0f86fb36eb260abd10007b62c9dcc1028e03e61

Timelineinfo

08/15/2026 CVE reserved
08/22/2026 +7 days Advisory disclosed
08/22/2026 +0 days VulDB entry created
08/23/2026 +1 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-74705 (🔒)
GCVE (CVE): GCVE-0-2026-74705
GCVE (VulDB): GCVE-100-394496

Entryinfo

Created: 08/22/2026 19:05
Updated: 08/23/2026 09:57
Changes: 08/22/2026 19:05 (59), 08/23/2026 09:57 (2)
Complete: 🔍
Cache ID: 216::103

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

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