CVE-2026-89951

Freed network-device dereference via merged fragments

Published Sep 16, 2026 · Updated Sep 16, 2026

Use-after-free in the Linux batman-adv receive path allows attackers to dereference a freed net_device via merged network fragments. Fragment reassembly reuses the highest-numbered fragment buffer without refreshing skb->dev or skb_iif before reinjection, so DAT or bridge-loop-avoidance parsing can access a deleted hard interface. Reachability requires that interface to be deleted before the fragment chain completes; published material does not state a resulting crash or other concrete impact.

CVSS severityUnavailable
Unscored
EPSS probabilityUnavailable
No score available in this record
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

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Summary

What happened

Use-after-free in the Linux batman-adv receive path allows attackers to dereference a freed net_device via merged network fragments. Fragment reassembly reuses the highest-numbered fragment buffer without refreshing skb->dev or skb_iif before reinjection, so DAT or bridge-loop-avoidance parsing can access a deleted hard interface. Reachability requires that interface to be deleted before the fragment chain completes; published material does not state a resulting crash or other concrete impact.

The record

CVE
CVE-2026-89951
Published
Sep 16, 2026
Updated
Sep 16, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=3.13
  2. Affected versionversion=610bfc6bc99bc83680d190ebc69359a05fc7f605 <2dffc8c44b6e3347b3719c6419c07b4a18fea895
  3. Affected versionversion=610bfc6bc99bc83680d190ebc69359a05fc7f605 <63d86250fa7cbe22451369bd1c0881dfc8190958
  4. Affected versionversion=610bfc6bc99bc83680d190ebc69359a05fc7f605 <6df64825f8b199921120c685af2abca14b077331
  5. Affected versionversion=610bfc6bc99bc83680d190ebc69359a05fc7f605 <a2c272da99c2077088083c14961cf2f1e4506995
  6. Affected versionversion=610bfc6bc99bc83680d190ebc69359a05fc7f605 <ad46c907d7d9975a285c1e89a4adde652eaa93f5
  7. Affected versionversion=610bfc6bc99bc83680d190ebc69359a05fc7f605 <e91d2cc7441d89a45bad73ad9789159c7441cb80
  8. Affected versionversion=610bfc6bc99bc83680d190ebc69359a05fc7f605 <f4b4ae763b5d59319fad62a00c76676758e7dafa
  9. Affected versionversion=610bfc6bc99bc83680d190ebc69359a05fc7f605 <f830c2dfc1431764db9256b3d5db1695fc9a7f56

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=3.13; version=610bfc6bc99bc83680d190ebc69359a05fc7f605 <2dffc8c44b6e3347b3719c6419c07b4a18fea895; version=610bfc6bc99bc83680d190ebc69359a05fc7f605 <63d86250fa7cbe22451369bd1c0881dfc8190958; version=610bfc6bc99bc83680d190ebc69359a05fc7f605 <6df64825f8b199921120c685af2abca14b077331; version=610bfc6bc99bc83680d190ebc69359a05fc7f605 <a2c272da99c2077088083c14961cf2f1e4506995; version=610bfc6bc99bc83680d190ebc69359a05fc7f605 <ad46c907d7d9975a285c1e89a4adde652eaa93f5; version=610bfc6bc99bc83680d190ebc69359a05fc7f605 <e91d2cc7441d89a45bad73ad9789159c7441cb80; version=610bfc6bc99bc83680d190ebc69359a05fc7f605 <f4b4ae763b5d59319fad62a00c76676758e7dafa; version=610bfc6bc99bc83680d190ebc69359a05fc7f605 <f830c2dfc1431764db9256b3d5db1695fc9a7f56

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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