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CVE-2026-52985 Linux CVE debrief

The Linux kernel was vulnerable to an uninit-value issue in the netdevsim component. This was caused by the use of skb_put instead of skb_put_zero, leading to uninitialized IP headers in dummy sk_buff. The issue was addressed by replacing skb_put with skb_put_zero to guarantee zero initialization of the whole IP header. This vulnerability could potentially allow an attacker to leak uninitialized data. Linux kernel users and administrators should be aware of this vulnerability and ensure they are running a patched version of the kernel.

Vendor
Linux
Product
Unknown
CVSS
MEDIUM 5.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-24
Original CVE updated
2026-07-14
Advisory published
2026-06-24
Advisory updated
2026-07-14

Who should care

Linux kernel users and administrators should be aware of this vulnerability and ensure they are running a patched version of the kernel. They should inventory Linux kernel versions and assess for exposure, apply patches or updates provided by the Linux kernel maintainers, monitor for potential exploitation attempts, and consider implementing compensating controls for affected systems.

Technical summary

The vulnerability was found in the netdevsim component of the Linux kernel. The issue arose from the use of skb_put, which does not initialize the allocated memory. An attacker could potentially exploit this to leak uninitialized data. The fix involves replacing skb_put with skb_put_zero, ensuring that the IP header is fully initialized. This change guarantees that the IP header in dummy sk_buff is zero-initialized, preventing potential data leaks.

Defensive priority

Medium

Recommended defensive actions

  • Inventory Linux kernel versions and assess for exposure
  • Apply patches or updates provided by the Linux kernel maintainers
  • Monitor for potential exploitation attempts
  • Consider implementing compensating controls for affected systems
  • Review 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
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record was published on 2026-06-24T17:17:09.260Z and last modified on 2026-07-10T19:24:19.850Z. The NVD entry is currently Awaiting Analysis. This issue is related to the netdevsim component of the Linux kernel. The vulnerability arises from the use of skb_put, which does not initialize the allocated memory. The fix involves replacing skb_put with skb_put_zero, ensuring that the IP header is fully initialized. Linux kernel users and administrators should verify their kernel versions and apply patches or updates provided by the Linux kernel maintainers.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-52985 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-52985

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

  • CVE-2026-52985 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-52985

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

Supplemental references

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/175556c049eaec14efde8c6475e763b7579b9de7

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/1b7b6ae0e93b8d512e208b1378d74af052e4f4e7

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/35eaa6d8d6c2ee65e96f507add856e0eacf24591

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/6e2cfd0904976e701d7a76b86b694e72af230ab0

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/750d0091bebf44975421268d37484ef87060d263

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/818f7673ed7f4a29d4b9cee8184c47d6e57162b4

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/978ca6ff789f1f19c03288ac20cc1f4774e88490

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

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.