Linux Kernel up to 7.1.8 ip6_tunnel ip6ip6_err cb/dsthao stack-based overflow

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.
9.5	$5k-$25k	0.00

Summaryinfo

A vulnerability classified as very critical has been found in Linux Kernel up to 7.1.8. The impacted element is the function ip6ip6_err of the component ip6_tunnel. The manipulation of the argument cb/dsthao leads to stack-based overflow. This vulnerability is traded as CVE-2026-74597. It is possible to initiate the attack remotely. There is no exploit available. It is recommended 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. This issue affects the function ip6ip6_err of the component ip6_tunnel. The manipulation of the argument cb/dsthao with an unknown input leads to a stack-based overflow vulnerability. Using CWE to declare the problem leads to CWE-121. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). Impacted is confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: ip6_tunnel: clear skb2->cb[] in ip6ip6_err() ip6ip6_err() clones an outer IPv6 ICMP error skb, pulls it to the quoted inner IPv6 packet, and then passes the clone to icmpv6_send(). The clone still carries the outer packet's inet6_skb_parm in skb->cb. If the outer packet had a Home Address Option, IP6CB(skb2)->dsthao remains non-zero after skb_pull(). icmpv6_send() later calls mip6_addr_swap(), which uses that stale dsthao offset against the quoted inner packet. A malformed inner destination-options header can then make the HAO lookup and address swap run past the end of the quoted packet and corrupt skb_shared_info. Clear skb2->cb[] before pulling the quoted inner IPv6 packet so the reply path does not reuse metadata left by the outer IPv6 stack.

It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2026-74597 since 08/15/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. 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 09/06/2026).

The vulnerability scanner Nessus provides a plugin with the ID 343049 (Oracle Linux 10 / 9 : Unbreakable Enterprise kernel (ELSA-2026-500248)), 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 44fe898df302e91c5ee5acbc71ffa74e78e6c183/0dadb0620ab65949a8bc2439dd28ea3c942fe87d/b6816536a2990c0db44a26130a03e40b441e829b/64e41736a26f37ab6215bc2e6df125df05aceb08/484134e1eb07d700a73b1e4bbf3fb503e299be60/4eb15c465337b18f44716c499cd6ad63eee0ad54/fbf40faa0414b753212494ad197542002e66ed9e/f803c086399da277b5d0ff36a107d0f162751800 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 databases at Tenable (343049) and CERT Bund (WID-SEC-2026-2970). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

• Open Source Linux Kernel

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.10.264
• 5.15.215
• 6.1.182
• 6.6.151
• 6.12.103
• 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
• 6.18.40
• 6.18.41
• 6.18.42
• 6.18.43
• 6.18.44
• 7.1.0
• 7.1.1
• 7.1.2
• 7.1.3
• 7.1.4
• 7.1.5
• 7.1.6
• 7.1.7
• 7.1.8

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
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CPE 2.2info

• 🔒
• 🔒
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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

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: Stack-based overflow
CWE: CWE-121 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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

Nessus ID: 343049
Nessus Name: Oracle Linux 10 / 9 : Unbreakable Enterprise kernel (ELSA-2026-500248)

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: 44fe898df302e91c5ee5acbc71ffa74e78e6c183/0dadb0620ab65949a8bc2439dd28ea3c942fe87d/b6816536a2990c0db44a26130a03e40b441e829b/64e41736a26f37ab6215bc2e6df125df05aceb08/484134e1eb07d700a73b1e4bbf3fb503e299be60/4eb15c465337b18f44716c499cd6ad63eee0ad54/fbf40faa0414b753212494ad197542002e66ed9e/f803c086399da277b5d0ff36a107d0f162751800

Timelineinfo

08/15/2026 CVE reserved
08/22/2026 +7 days Advisory disclosed
08/22/2026 +0 days VulDB entry created
09/06/2026 +15 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-74597 (🔒)
GCVE (CVE): GCVE-0-2026-74597
GCVE (VulDB): GCVE-100-394379
CERT Bund: WID-SEC-2026-2970 - Linux Kernel: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff

Entryinfo

Created: 08/22/2026 17:59
Updated: 09/06/2026 22:00
Changes: 08/22/2026 17:59 (60), 08/24/2026 20:30 (7), 09/06/2026 22:00 (2)
Complete: 🔍
Cache ID: 216::103

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

Discussion

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