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CVE Record

CVE-2026-46331: net/sched: fix pedit partial COW leading to page cache corruption

In the Linux kernel, the following vulnerability has been resolved: net/sched: fix pedit partial COW leading to page cache corruption tcf_pedit_act() computes the COW range for skb_ensure_writable() once before the key loop using tcfp_off_max_hint, but the hint does not account for the runtime header offset added by typed keys. This can leave part of the write region un-COW'd. Fix by moving skb_ensure_writable() inside the per-key loop where the actual write offset is known, and add overflow checking on the offset arithmetic. For negative offsets (e.g. Ethernet header edits at ingress), use skb_cow() to COW the headroom instead. Guard offset_valid() against INT_MIN, where negation is undefined.

HighCVSS 7.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

This is a high-severity Linux kernel flaw that can let a local, low-privileged attacker corrupt kernel-managed memory through packet editing behavior. The business risk is strongest on shared Linux hosts, container platforms, and systems where local users are not fully trusted.

Executive priority

Treat as priority patching for Linux fleets with shared-user, hosting, CI, or container workloads. It is not listed in KEV, but the impact rating and public exploit reference justify accelerated remediation.

Technical view

The flaw is in net/sched pedit handling. tcf_pedit_act() calculated the writable copy-on-write range before knowing per-key runtime offsets, leaving part of the write region outside COW protection. Upstream fixes move skb_ensure_writable() into the key loop, add offset overflow checks, and handle negative offsets with skb_cow().

Likely exposure

Exposure is Linux kernel dependent. The bundle lists Linux as affected and includes upstream stable fixes plus Red Hat advisories. Validate against your distribution kernel, not only upstream version strings, because vendor backports may change exposure.

Exploitation context

The CVSS vector is local, low complexity, low privileges, no user interaction, with high confidentiality, integrity, and availability impact. KEV is false. A public GitHub reference is tagged exploit, but the supplied sources do not prove active in-the-wild exploitation.

Researcher notes

The core issue is partial COW coverage in pedit writes caused by offset calculation before runtime typed-key offsets. Avoid assuming every listed upstream version maps directly to a vendor package; confirm backports and advisory status per distribution.

Mitigation direction

  • Apply vendor kernel updates that address CVE-2026-46331.
  • Use Red Hat errata if running affected Red Hat products.
  • Track upstream stable commits if vendor packages are pending.
  • Review local user and container privilege exposure until patched.
  • Follow vendor guidance for any product-specific mitigations.

Validation and detection

  • Inventory Linux kernels across servers, containers hosts, and appliances.
  • Compare installed vendor kernel packages against advisory fixed versions.
  • Confirm whether Red Hat errata apply to your product stream.
  • Verify upstream stable fix commits are present or backported.
  • Check vulnerability scanner results against vendor advisories.
Prepared
Confidence
medium
Sources
12

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-190: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
cwe · low confidence lookup

CWE-787: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2026-46331 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
High
CVSS
7.8 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
5Timeline events
2ADP providers
44Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: pocAutomatable: noTechnical Impact: total

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
7.8CVSS 3.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9Linux
6.7CVSS 3.1MediumCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H0.85.9redhat-SADP

Vulnerability scoring details

Base CVSS 3.1 score

7.8High
CVSS 3.1 vector shape for CVE-2026-46331Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. ADP timelineredhat-SADP

    Made public.

  3. ADP timelineredhat-SADP

    Reported to Red Hat.

  4. CVE publishedCVE Program

    The CVE record was published.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
redhat-SADPkernel: net/sched: act_pedit: extend the writable skb range per key
other:Red Hat severity ratingcvssV3_1
  • 2026-05-18T06:17:23.219Z: Reported to Red Hat.
  • 2026-05-18T04:04:00.000Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxabe35bf3be51482593076d516a680d79e5fbc8e1, b773640d5bb9e2acfd91e2695717af04d47aa116, 8b796475fd7882663a870456466a4fb315cc1bd6, 8b796475fd7882663a870456466a4fb315cc1bd6, 8b796475fd7882663a870456466a4fb315cc1bd6, 8b796475fd7882663a870456466a4fb315cc1bd6, 8b796475fd7882663a870456466a4fb315cc1bd6, 8b796475fd7882663a870456466a4fb315cc1bd6, d0c38a914b0c4c21d553da801003d36979016726, 2ec2dd7d51a9320151f275ddbb2b53260fb32ca1, c19cc520b3d69904e9518d401ad0df7f4702aca0, 5.10.117, 5.15.41, 4.19.244, 5.4.195, 5.17.9unaffected
LinuxLinux5.18, 0, 5.10.260, 5.15.211, 6.1.177, 6.6.144, 6.12.94, 6.18.36, 7.0.13, 7.1affected
Weakness

CWE details

CWE-190CWE-787

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-190 · source CWE mapping

Integer Overflow or Wraparound

Integer Overflow or Wraparound represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs
CWE-787 · source CWE mapping

Out-of-bounds Write

Out-of-bounds Write represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs