PatchSiren

PatchSiren cyber security CVE debrief

CVE-2026-74597 Linux CVE debrief

A critical vulnerability in the Linux kernel's ip6_tunnel component has been patched. The issue arises from improper handling of IPv6 ICMP error packets, which can lead to memory corruption and potential code execution. This vulnerability affects various Linux kernel versions and has been addressed by the Linux community. The patch provided by the Linux community fixes the issue by clearing skb2->cb[] in ip6ip6_err(). Linux administrators and users, network security teams, and individuals responsible for maintaining Linux-based systems should be aware of this vulnerability and take steps to apply the patches or updates provided by the Linux community. The vulnerability can be mitig

Vendor
Linux
Product
Unknown
CVSS
CRITICAL 9.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-08-22
Original CVE updated
2026-10-16
Advisory published
2026-08-22
Advisory updated
2026-10-16

Who should care

Linux administrators and users, network security teams, and individuals responsible for maintaining Linux-based systems should be aware of this vulnerability and take steps to apply the patches or updates provided by the Linux community.

Why it matters

CVE-2026-74597 is a critical vulnerability in the Linux kernel's ip6_tunnel component that requires immediate attention from Linux administrators and security teams. The vulnerability can lead to memory corruption and potential code execution if exploited. Affected systems should be patched or mitigated promptly to prevent potential disruption or exploitation.

  • Potential memory corruption and code execution via specially crafted IPv6 ICMP error packets.
  • Possible disruption of network services or system crashes if exploited.
  • Need for prompt patching or mitigation to prevent potential exploitation.
  • Verification of Linux kernel versions and application of patches is crucial.

Technical summary

The Linux kernel's ip6_tunnel component is vulnerable to a critical issue (CVE-2026-74597) that can lead to memory corruption. The vulnerability arises from improper handling of IPv6 ICMP error packets. The issue has been patched by the Linux community, and affected kernel versions should be updated to prevent potential exploitation. The patch provided by the Linux community fixes the issue by clearing skb2->cb[] in ip6ip6_err(). The vulnerability can be mitigated by applying the patches or updates provided by the Linux community. It is essential to review and apply the patches provided by the Linux community for the affected kernel versions.

Defensive priority

High

Recommended defensive actions

  • Review and apply the patches provided by the Linux community for the affected kernel versions.
  • Ensure that the Linux kernel is updated to a version that includes the fix.
  • Monitor network traffic for suspicious IPv6 ICMP error packets.
  • Verify Linux kernel versions and apply patches or mitigations promptly.
  • Review compensating controls for exposed systems while remediation is scheduled and verified.
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review.
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented.

Evidence notes

The CVE record and associated source item provide details on the vulnerability, including its description, affected versions, and references to patches. However, specific details about exploitation or victim impact are not provided.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-74597 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-74597

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-74597 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-74597

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • ip6_tunnel: clear skb2->cb[] in ip6ip6_err()

    Unverified legacy reference

    URL: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/74xxx/CVE-2026-74597.json

    cve_program_cvelist_v5

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/44fe898df302e91c5ee5acbc71ffa74e78e6c183

    Supplemental source

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/0dadb0620ab65949a8bc2439dd28ea3c942fe87d

    Supplemental source

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/b6816536a2990c0db44a26130a03e40b441e829b

    Supplemental source

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/64e41736a26f37ab6215bc2e6df125df05aceb08

    Supplemental source

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/484134e1eb07d700a73b1e4bbf3fb503e299be60

    Supplemental source

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/4eb15c465337b18f44716c499cd6ad63eee0ad54

    Supplemental source

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/fbf40faa0414b753212494ad197542002e66ed9e

    Supplemental source

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.