Unknown

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

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.

Published Sep 16, 2026 · Updated Oct 19, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: Linux

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.2% (30-day exploitation probability)+2

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.21%

ahead of 11% of scored CVEs · Oct 19, 2026

Affects

Linux

CVSS base

—

Score not published yet.

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Linux	Linux	≥ 23721387c409087fd3b97e274f34d3ddc0970b74 and < 844a95a734f178d56c7acce14c5cce2cecff7e1a≥ 23721387c409087fd3b97e274f34d3ddc0970b74 and < baeb1a28fd8e2f68193650d3664a8cd1adfd85c6≥ 23721387c409087fd3b97e274f34d3ddc0970b74 and < aacffa780a37e06cd5a13d33740a6e96c3a67e6c≥ 23721387c409087fd3b97e274f34d3ddc0970b74 and < 76aedcde5a2489cc971d4d1e396e784a49565e96≥ 23721387c409087fd3b97e274f34d3ddc0970b74 and < f50edb69082a8ba990cc23d642089829f99afe6a≥ 23721387c409087fd3b97e274f34d3ddc0970b74 and < 871acdf97f64cee8398f72b88b89e8b4f4816dbe≥ 23721387c409087fd3b97e274f34d3ddc0970b74 and < 9a0c47023d3254048a1588534755d4476bcc3abc≥ 23721387c409087fd3b97e274f34d3ddc0970b74 and < 8d128c932bced74e3b1625ba3d7c78ef122a88a7 and 1 more version 3.5	Vulnerable	CVE Program (cve.org) e CISA ADP

EPSS over time FIRST

Oct 15, 2026 → Oct 19, 2026 · 4 reading(s) · max 0.21%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Not enough vector or weakness data: use the affected application’s logs as a starting point.

application logs

Timeline

What happened to this CVE, newest first.

2026
Record published
Oct 15, 2026
Affected products added · linux/linux
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Source status changed · → Received
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Sep 16, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

1× References added · Oct 19, 2026 – Oct 19, 2026
1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

10 on the record

github.com/advisories/GHSA-9m5r-cr5m-2hhr
GitHub Security Advisories
git.kernel.org/stable/c/871acdf97f64cee8398f72b88b89e8b4f4816dbe
NIST National Vulnerability Database
git.kernel.org/stable/c/8d128c932bced74e3b1625ba3d7c78ef122a88a7
NIST National Vulnerability Database
git.kernel.org/stable/c/9a0c47023d3254048a1588534755d4476bcc3abc
NIST National Vulnerability Database
git.kernel.org/stable/c/76aedcde5a2489cc971d4d1e396e784a49565e96
NIST National Vulnerability Database
git.kernel.org/stable/c/baeb1a28fd8e2f68193650d3664a8cd1adfd85c6
NIST National Vulnerability Database
git.kernel.org/stable/c/f50edb69082a8ba990cc23d642089829f99afe6a
NIST National Vulnerability Database
git.kernel.org/stable/c/844a95a734f178d56c7acce14c5cce2cecff7e1a
NIST National Vulnerability Database
nvd.nist.gov/vuln/detail/CVE-2026-89948
GitHub Security Advisories
git.kernel.org/stable/c/aacffa780a37e06cd5a13d33740a6e96c3a67e6c
NIST National Vulnerability Database

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

Unknown CVE-2026-98866 sched/cache: Introduce task_struct->sched_cache_grp to fix UAF 1d
Unknown CVE-2026-98867 dm-pcache: bound the logical key offset from persistent memory 1d
Unknown CVE-2026-98868 dm-pcache: reject a kset that overruns its segment 1d
Unknown CVE-2026-98856 kprobes: Skip disarmed probes when checking optkprobe overlap 1d
Unknown CVE-2026-98857 ipvs: bound LBLCR and LBLC cache growth 1d
Unknown CVE-2026-98858 io_uring: fix task_work add use-after-free with SQPOLL 1d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No CVSS score published by NVD, the CNA, CISA or GitHub so far.
No fixed version, patch or mitigation documented.
No CISA SSVC assessment.
No CWE classification.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-89948 is "batman-adv: bla: fix freeing of claims on meshif deletion", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.21% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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