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CVE Record

CVE-2026-46212: batman-adv: bla: prevent use-after-free when deleting claims

In the Linux kernel, the following vulnerability has been resolved: batman-adv: bla: prevent use-after-free when deleting claims When batadv_bla_del_backbone_claims() removes all claims for a backbone, it does this by dropping the link entry in the hash list. This list entry itself was one of the references which need to be dropped at the same time via batadv_claim_put(). But the batadv_claim_put() must not be done before the last access to the claim object in this function. Otherwise the claim might be freed already by the batadv_claim_release() function before the list entry was dropped.

HighCVSS 8.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

A memory-safety flaw in Linux’s batman-adv mesh-networking code can access a claim object after it has been freed. An adjacent, unauthenticated attacker may be able to compromise confidentiality, integrity, or availability when the affected functionality is in use. Systems not using batman-adv have substantially lower practical exposure.

Executive priority

Treat this as a high-priority patching issue for active batman-adv mesh deployments, especially those admitting untrusted adjacent devices. Routine Linux systems without this module in use are lower priority. Ask infrastructure owners to establish deployment-specific exposure and upgrade status promptly.

Technical view

batadv_bla_del_backbone_claims() could call batadv_claim_put() before its final access to a claim and before removing the associated hash-list entry. The resulting premature release creates a use-after-free condition. The supplied CVSS 3.1 score is 8.8 with an adjacent-network, low-complexity, no-privilege, no-user-interaction vector.

Likely exposure

Prioritize Linux systems using the batman-adv module and bridge loop avoidance functionality on networks reachable by untrusted adjacent participants. The supplied affected-version data is ambiguously structured, so confirm exposure against distribution advisories and the referenced stable-kernel fixes rather than relying solely on version strings.

Exploitation context

The supplied record does not identify this CVE as CISA KEV-listed and provides no evidence of active exploitation or a public exploit. The adjacent-network vector limits exposure compared with an internet-routable flaw, but unauthenticated reachability and potential high impact make affected mesh deployments important to address.

Researcher notes

The flaw concerns claim lifetime and reference ordering during backbone-claim deletion. The source bundle supplies multiple stable-tree correction commits but does not map each commit clearly to every listed version. It also supplies no crash signature, exploit evidence, or vendor-specific package mapping; validate those details through applicable distribution guidance.

Mitigation direction

  • Apply a vendor-supported kernel update containing the applicable referenced stable fix.
  • Check Linux distribution advisories for corrected package versions and required reboot instructions.
  • Prioritize exposed mesh nodes where untrusted devices can participate on adjacent networks.
  • Follow vendor guidance for interim controls if an immediate kernel update is unavailable.

Validation and detection

  • Inventory kernels with batman-adv installed, loaded, or configured for mesh networking.
  • Determine whether bridge loop avoidance functionality is enabled on each relevant node.
  • Compare running kernel packages with distribution advisories and referenced stable commits.
  • After updating, verify the corrected kernel is running following any required reboot.
  • Monitor affected nodes for crashes or anomalous behavior; these indicators do not prove exploitation.
Prepared
Confidence
medium
Sources
10

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.

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CVE-2026-46212 mapping review

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Vulnerability profileCVE Program record
Severity
High
CVSS
8.8 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:A/AC:L/PR:N/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
9Source 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
8.8CVSS 3.1HighCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H2.85.9Linux

Vulnerability scoring details

Base CVSS 3.1 score

8.8High
CVSS 3.1 vector shape for CVE-2026-46212Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:A/AC:L/PR:N/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
LinuxLinux23721387c409087fd3b97e274f34d3ddc0970b74, 23721387c409087fd3b97e274f34d3ddc0970b74, 23721387c409087fd3b97e274f34d3ddc0970b74, 23721387c409087fd3b97e274f34d3ddc0970b74, 23721387c409087fd3b97e274f34d3ddc0970b74, 23721387c409087fd3b97e274f34d3ddc0970b74, 23721387c409087fd3b97e274f34d3ddc0970b74, 23721387c409087fd3b97e274f34d3ddc0970b74unaffected
LinuxLinux3.5, 0, 5.10.258, 5.15.209, 6.1.175, 6.6.140, 6.12.90, 6.18.32, 7.0.9, 7.1affected
Weakness

CWE details

No CWE listed

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