LiveActive security incident?Get immediate response
CVE Record

CVE-2026-45951: bpf: Fix a potential use-after-free of BTF object

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix a potential use-after-free of BTF object Refcounting in the check_pseudo_btf_id() function is incorrect: the __check_pseudo_btf_id() function might get called with a zero refcounted btf. Fix this, and patch related code accordingly. v3: rephrase a comment (AI) v2: fix a refcount leak introduced in v1 (AI)

HighCVSS 7.8Not KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

A Linux kernel BPF flaw can leave a BTF object in use after it has been freed because its reference count is handled incorrectly. A local, low-privileged attacker could potentially compromise confidentiality, integrity, and availability. The supplied assessment scores it 7.8 High.

Executive priority

Treat as a high-priority kernel update for systems with untrusted local users. Internet exposure alone does not establish reachability because the stated attack vector is local. Accelerate vendor verification and patching where low-privileged access exists.

Technical view

The flaw occurs in check_pseudo_btf_id(): __check_pseudo_btf_id() may receive a BTF object whose reference count is already zero, creating a potential use-after-free. Linux stable commits correct the reference handling and related code.

Likely exposure

Exposure requires local access with low privileges and access to the affected BPF path; user interaction is unnecessary. The bundle marks Linux releases as affected but presents ambiguous version boundaries and duplicate commit data. Confirm exact exposure against distribution guidance and backport records.

Exploitation context

The CVSS vector indicates local, low-complexity exploitation requiring low privileges, with potentially high confidentiality, integrity, and availability impact. The bundle says this CVE is not in KEV and provides no evidence of active exploitation or a public exploit.

Researcher notes

The source identifies a BTF reference-counting defect and three Linux stable commits. It does not provide CWE classification, exploitability details beyond CVSS, or an unambiguous affected-version range. Distribution backports may make kernel version strings insufficient for determining vulnerability status.

Mitigation direction

  • Install a vendor-supported kernel update incorporating the applicable referenced stable fix.
  • Check Linux distribution advisories for exact fixed package versions and backport status.
  • Prioritize systems where untrusted or low-privileged users have local access.
  • Consider restricting affected BPF access until patched, subject to vendor guidance and operational requirements.

Validation and detection

  • Inventory running kernel versions across Linux systems.
  • Compare each kernel package with distribution advisories and backport records.
  • Confirm the installed kernel includes the applicable stable fix.
  • Reboot updated systems where required, then verify the running kernel version.
  • Test legitimate BPF-dependent workloads after remediation.
Prepared
Confidence
medium
Sources
5

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.

cve · low confidence lookup

CVE-2026-45951 mapping review

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

Open ATT&CK lookup
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.

1CVSS vectors
3Timeline events
0ADP providers
4Source links

CVSS vector scores

1 official score

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

Vulnerability scoring details

Base CVSS 3.1 score

7.8High
CVSS 3.1 vector shape for CVE-2026-45951Attack 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. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

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

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux76145f7255326761dafb76721a785799d8a00d5f, 76145f7255326761dafb76721a785799d8a00d5f, 76145f7255326761dafb76721a785799d8a00d5funaffected
LinuxLinux6.14, 0, 6.18.14, 6.19.4, 7.0affected
Weakness

CWE details

No CWE listed

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