Skip to content
Noroxi
NVD / CVE Program· CNA Linux

CVE-2026-89951: batman-adv: fix stale receive device on merged fragments

Noroxi assessment

Priority: Monitor (action score 35/100)

  • 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: 0.35% (FIRST EPSS).
  • Someone on the same network segment can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 2dffc8c44b6e3347b3719c6419c07b4a18fea895, 63d86250fa7cbe22451369bd1c0881dfc8190958, 6df64825f8b199921120c685af2abca14b077331.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 2dffc8c44b6e3347b3719c6419c07b4a18fea895, 63d86250fa7cbe22451369bd1c0881dfc8190958, 6df64825f8b199921120c685af2abca14b077331 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: fix stale receive device on merged fragments Fragment reassembly reuses the skb from the highest-numbered buffered fragment as the merged packet. When that fragment was received on a hard interface which is deleted before the chain completes, the merged skb can re-enter the receive path with a stale skb->dev and skb_iif. batadv_batman_skb_recv() passes such merged packets through the normal receive handlers again. DAT and bridge loop avoidance both derive the ARP header length from skb->dev, so they can dereference the freed net_device before the packet reaches the local mesh interface. Refresh the receive device metadata from the current receive device before running the packet handlers. This keeps internally reinjected merged fragments consistent with the normal receive path after hard interface teardown.

HighCVSS 8.8 · v3.1—No exploit Fix available
Published
Sep 16, 2026
Updated
Oct 19, 2026
EPSS
0.3% · 29th percentile
CWE
—

Report tools

JSON

Action score

35

Monitor

Low priority for now.

CVSS
35 / 40 · 8.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CNA vs NVD score

NVD
—
CNA · Linux
8.8
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

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

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-89951

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

Your free account also gets you

Running WordPress? Scan your site free with WP Lens

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for linux records

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

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.

We use this product, ask for help

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

    • 3.13affected
    • 610bfc6bc99bc83680d190ebc69359a05fc7f605 and later · before 63d86250fa7cbe22451369bd1c0881dfc8190958affected · git
    • 610bfc6bc99bc83680d190ebc69359a05fc7f605 and later · before f830c2dfc1431764db9256b3d5db1695fc9a7f56affected · git
    • 610bfc6bc99bc83680d190ebc69359a05fc7f605 and later · before f4b4ae763b5d59319fad62a00c76676758e7dafaaffected · git
    • 610bfc6bc99bc83680d190ebc69359a05fc7f605 and later · before 6df64825f8b199921120c685af2abca14b077331affected · git
    • 610bfc6bc99bc83680d190ebc69359a05fc7f605 and later · before a2c272da99c2077088083c14961cf2f1e4506995affected · git
    • 610bfc6bc99bc83680d190ebc69359a05fc7f605 and later · before e91d2cc7441d89a45bad73ad9789159c7441cb80affected · git
    • 610bfc6bc99bc83680d190ebc69359a05fc7f605 and later · before 2dffc8c44b6e3347b3719c6419c07b4a18fea895affected · git
    • 610bfc6bc99bc83680d190ebc69359a05fc7f605 and later · before ad46c907d7d9975a285c1e89a4adde652eaa93f5affected · git
    • before 3.13not 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-2026-89949Sep 16, 2026 · batman-adv: dat: avoid unaligned fault in IP extraction
    0Monitor
  • ← EarlierCVE-2026-89950Sep 16, 2026 · batman-adv: mcast: linearize skbuff for packet generation
    0Monitor
  • Later →CVE-2026-89952Sep 16, 2026 · mtd: rawnand: validate ONFI extended parameter page sections
    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 Linux2dffc8c44b6e3347b3719c6419c07b4a18fea895Vendor (CNA)
Linux Linux63d86250fa7cbe22451369bd1c0881dfc8190958Vendor (CNA)
Linux Linux6df64825f8b199921120c685af2abca14b077331Vendor (CNA)
Linux Linuxa2c272da99c2077088083c14961cf2f1e4506995Vendor (CNA)
Linux Linuxad46c907d7d9975a285c1e89a4adde652eaa93f5Vendor (CNA)
Linux Linuxe91d2cc7441d89a45bad73ad9789159c7441cb80Vendor (CNA)
Linux Linuxf4b4ae763b5d59319fad62a00c76676758e7dafaVendor (CNA)
Linux Linuxf830c2dfc1431764db9256b3d5db1695fc9a7f56Vendor (CNA)
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

Attack conditions

  • Someone on the same network segment can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Adjacent
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd-secondary

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✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (7 more)

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

All records