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NVD / CVE Program· CNA Linux

CVE-2026-89948: batman-adv: bla: fix freeing of claims on meshif deletion

Noroxi assessment

Priority: Monitor (action score 0/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.21% (FIRST EPSS).
  • Fixed version: Linux Linux 76aedcde5a2489cc971d4d1e396e784a49565e96, 844a95a734f178d56c7acce14c5cce2cecff7e1a, 871acdf97f64cee8398f72b88b89e8b4f4816dbe; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 6.6.157.1-1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 76aedcde5a2489cc971d4d1e396e784a49565e96, 844a95a734f178d56c7acce14c5cce2cecff7e1a, 871acdf97f64cee8398f72b88b89e8b4f4816dbe; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 6.6.157.1-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: batman-adv: bla: fix freeing of claims on meshif deletion When the mesh interface is getting deleted, then batadv_bla_del_backbone_claims() (via batadv_bla_purge_backbone_gw()) could make sure that all claims gets removed. But this function is only executed when bat_priv->bla.claim_hash is not NULL. And since batadv_bla_free() is always setting it to NULL before it is (indirectly) called, it was never actually executed. But the batadv_bla_purge_claims() -> batadv_handle_unclaim() is at the moment too fragile because the BLA code is not handling the rehashing in batadv_bla_update_orig_address(). The stored backbone address doesn't have to be the one actually used for the hash bucket selection during the initial adding of the backbone. The batadv_handle_unclaim() can therefore fail to find the respective backbone for the unclaim and then stop the deletion. But the actual backbone_gw object is not needed for the unclaim because all relevant information is always provided by the caller. And the check for the existence of the backbone_gw doesn't provide any additional security check for the deletion of a claim.

—No exploit Fix available
Published
Sep 16, 2026
Updated
Oct 19, 2026
EPSS
0.2% · 12th percentile
CWE
—

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

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  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 3.5affected
    • 23721387c409087fd3b97e274f34d3ddc0970b74 and later · before 844a95a734f178d56c7acce14c5cce2cecff7e1aaffected · git
    • 23721387c409087fd3b97e274f34d3ddc0970b74 and later · before baeb1a28fd8e2f68193650d3664a8cd1adfd85c6affected · git
    • 23721387c409087fd3b97e274f34d3ddc0970b74 and later · before aacffa780a37e06cd5a13d33740a6e96c3a67e6caffected · git
    • 23721387c409087fd3b97e274f34d3ddc0970b74 and later · before 76aedcde5a2489cc971d4d1e396e784a49565e96affected · git
    • 23721387c409087fd3b97e274f34d3ddc0970b74 and later · before f50edb69082a8ba990cc23d642089829f99afe6aaffected · git
    • 23721387c409087fd3b97e274f34d3ddc0970b74 and later · before 871acdf97f64cee8398f72b88b89e8b4f4816dbeaffected · git
    • 23721387c409087fd3b97e274f34d3ddc0970b74 and later · before 9a0c47023d3254048a1588534755d4476bcc3abcaffected · git
    • 23721387c409087fd3b97e274f34d3ddc0970b74 and later · before 8d128c932bced74e3b1625ba3d7c78ef122a88a7affected · git
    • before 3.5not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.190-16.1.190-1
Debian:12linux-6.12before 6.12.111-1~deb12u16.12.111-1~deb12u1
Debian:13linuxbefore 6.12.111-16.12.111-1
Debian:14linuxbefore 7.2.6-17.2.6-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-89946Sep 16, 2026 · ASoC: cs35l33: drain threaded IRQ before runtime suspend
    0Monitor
  • ← EarlierCVE-2026-89947Sep 16, 2026 · clk: meson: align gxbb_32k_clk_sel number of parents with actual count
    32Monitor
  • Later →CVE-2026-89949Sep 16, 2026 · batman-adv: dat: avoid unaligned fault in IP extraction
    0Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux76aedcde5a2489cc971d4d1e396e784a49565e96Vendor (CNA)
Linux Linux844a95a734f178d56c7acce14c5cce2cecff7e1aVendor (CNA)
Linux Linux871acdf97f64cee8398f72b88b89e8b4f4816dbeVendor (CNA)
Linux Linux8d128c932bced74e3b1625ba3d7c78ef122a88a7Vendor (CNA)
Linux Linux9a0c47023d3254048a1588534755d4476bcc3abcVendor (CNA)
Linux Linuxaacffa780a37e06cd5a13d33740a6e96c3a67e6cVendor (CNA)
Linux Linuxbaeb1a28fd8e2f68193650d3664a8cd1adfd85c6Vendor (CNA)
Linux Linuxf50edb69082a8ba990cc23d642089829f99afe6aVendor (CNA)
azl3 kernel 6.6.150.1-1 on Azure Linux 3.0—Microsoft (MSRC)
azl3 kernel 6.6.152.1-1 on Azure Linux 3.06.6.157.1-1 · Release NotesMicrosoft (MSRC)
debian:linux6.1.190-1 · Debian:12Package registry (OSV)
debian:linux6.12.111-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.111-1~deb12u1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

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References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records