GHSA-9M5R-CR5M-2HHR
Vulnerability from github – Published: 2026-09-16 12:30 – Updated: 2026-09-16 12:30In 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.
{
"affected": [],
"aliases": [
"CVE-2026-89948"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-09-16T11:17:04Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbatman-adv: bla: fix freeing of claims on meshif deletion\n\nWhen the mesh interface is getting deleted, then\nbatadv_bla_del_backbone_claims() (via batadv_bla_purge_backbone_gw()) could\nmake sure that all claims gets removed. But this function is only executed\nwhen bat_priv-\u003ebla.claim_hash is not NULL. And since batadv_bla_free() is\nalways setting it to NULL before it is (indirectly) called, it was never\nactually executed.\n\nBut the batadv_bla_purge_claims() -\u003e batadv_handle_unclaim() is at the\nmoment too fragile because the BLA code is not handling the rehashing in\nbatadv_bla_update_orig_address(). The stored backbone address doesn\u0027t have\nto be the one actually used for the hash bucket selection during the\ninitial adding of the backbone. The batadv_handle_unclaim() can therefore\nfail to find the respective backbone for the unclaim and then stop the\ndeletion.\n\nBut the actual backbone_gw object is not needed for the unclaim because all\nrelevant information is always provided by the caller. And the check for\nthe existence of the backbone_gw doesn\u0027t provide any additional security\ncheck for the deletion of a claim.",
"id": "GHSA-9m5r-cr5m-2hhr",
"modified": "2026-09-16T12:30:42Z",
"published": "2026-09-16T12:30:42Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89948"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/76aedcde5a2489cc971d4d1e396e784a49565e96"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/844a95a734f178d56c7acce14c5cce2cecff7e1a"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/871acdf97f64cee8398f72b88b89e8b4f4816dbe"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/8d128c932bced74e3b1625ba3d7c78ef122a88a7"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9a0c47023d3254048a1588534755d4476bcc3abc"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/aacffa780a37e06cd5a13d33740a6e96c3a67e6c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/baeb1a28fd8e2f68193650d3664a8cd1adfd85c6"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f50edb69082a8ba990cc23d642089829f99afe6a"
}
],
"schema_version": "1.4.0",
"severity": []
}
Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
How durations are calculated
Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.
Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.
Loading timeline…
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.