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CVE-2026-64091· NVD / CVE Program· CNA Linux

batman-adv: tt: fix TOCTOU race for reported vlans

Noroxi assessment

Priority: Monitor (action score 39/100)

  • 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: 0.42% (FIRST EPSS).
  • Anyone who can reach it over the internet 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 211ea59988e1cba43cb0367ad65d379b56f9c3bd, 3.17, 4.10.

Low priority for now. Upgrade to Linux Linux 211ea59988e1cba43cb0367ad65d379b56f9c3bd, 3.17, 4.10 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: tt: fix TOCTOU race for reported vlans The local TT based TVLV is generated by first checking the number of VLANs which have at least one TT entry. A new buffer with the correct size for the VLANs is then allocated. Only then, the list of VLANs s used to fill the VLAN entries in the buffer. During this time, the meshif_vlan_list_lock is held. But the actual number of TT entries of each VLAN can still increase during this time - just not the number of VLANs in the list. But the prefilter used in the buffer size calculation might still cause an increase of the number of VLANs which need to be stored. Simply because a VLAN might now suddenly have at least one entry when it had none in the pre-alloc check - and then needs to occupy space which was not allocated. It is better to overestimate the buffer size at the beginning and then fill the buffer only with the VLANs which are not empty.

CriticalCVSS 9.8 · v3.1—No exploit Fix available
Published
Jul 19, 2026
Updated
Aug 11, 2026
EPSS
0.4% · 35th percentile

Report tools

JSON

Action score

39

Monitor

Low priority for now.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CNA vs NVD score

NVD
—
CNA · Linux
9.8
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.

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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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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

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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.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel3.16.60 and later · before 3.17
  • linux linux kernel4.4.217 and later · before 4.5
  • linux linux kernel4.9.217 and later · before 4.10
  • linux linux kernel4.14.174 and later · before 4.15
  • linux linux kernel4.17.1 and later · before 5.10.259
  • linux linux kernel5.11 and later · before 5.15.210
  • linux linux kernel5.16 and later · before 6.1.176
  • linux linux kernel6.2 and later · before 6.6.143
  • linux linux kernel6.7 and later · before 6.12.93
  • linux linux kernel6.13 and later · before 6.18.34
  • linux linux kernel6.19 and later · before 7.0.11
  • linux linux kernel4.17
  • linux linux kernel7.1

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

    • 3134c5a32810c510f1f447c135cec346acbb71c3, e861e03a1b5b615ad1b57b1802b17e260eedccfe, 0b81edc8818903c64c4d121bc51cd5825be8cc67, 90ae6475b1753f0c1a4c66034b5666de3189fac8, 4.17affected
    • 16116dac23396e73c01eeee97b102e4833a4b205 and later · before e4236bf3ec8d6bb15d0d8d825dcf9933a7d6666baffected · git
    • 16116dac23396e73c01eeee97b102e4833a4b205 and later · before 724a8eb4155669797c96b70d70e354284ae3b5a8affected · git
    • 16116dac23396e73c01eeee97b102e4833a4b205 and later · before 211ea59988e1cba43cb0367ad65d379b56f9c3bdaffected · git
    • 16116dac23396e73c01eeee97b102e4833a4b205 and later · before 65a1e67339aa8c95ac544b796946af388930ee23affected · git
    • 16116dac23396e73c01eeee97b102e4833a4b205 and later · before b4d4efd4e351593c81e9293d4b4408d244fa5ee7affected · git
    • 16116dac23396e73c01eeee97b102e4833a4b205 and later · before 4cc85aec8d3c9ab4dc716dc9f1ed36fca16b227faffected · git
    • 16116dac23396e73c01eeee97b102e4833a4b205 and later · before 9a9c859457bc440a55773e01ff18b1bb5bab6836affected · git
    • 16116dac23396e73c01eeee97b102e4833a4b205 and later · before 94d27005016be15ffc638b2ecbc4d58805ad7b48affected · git
    • 3.16.60 and later · before 3.17affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.176-16.1.176-1
Debian:13linuxbefore 6.12.94-16.12.94-1
Debian:14linuxbefore 7.0.12-17.0.12-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now
  • CVE-2016-5195Race condition in mm/gup.c in the Linux kernel 2.x through 4.x before 4.8.3 allows local users to gain privileges by leveraging incorrect haKEV
    83Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-64089Jul 19, 2026 · batman-adv: tt: fix negative last_changeset_len
    39Monitor
  • ← EarlierCVE-2026-64090Jul 19, 2026 · batman-adv: tt: avoid empty VLAN responses
    22Monitor
  • Later →CVE-2026-64092Jul 19, 2026 · batman-adv: tp_meter: fix tp_vars reference leak in receiver shutdown
    22Monitor

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 Linux211ea59988e1cba43cb0367ad65d379b56f9c3bdVendor (CNA)
Linux Linux3.17Vendor (CNA)
Linux Linux4.10Vendor (CNA)
Linux Linux4.15Vendor (CNA)
Linux Linux4.5Vendor (CNA)
Linux Linux4cc85aec8d3c9ab4dc716dc9f1ed36fca16b227fVendor (CNA)
Linux Linux65a1e67339aa8c95ac544b796946af388930ee23Vendor (CNA)
Linux Linux724a8eb4155669797c96b70d70e354284ae3b5a8Vendor (CNA)
Linux Linux94d27005016be15ffc638b2ecbc4d58805ad7b48Vendor (CNA)
Linux Linux9a9c859457bc440a55773e01ff18b1bb5bab6836Vendor (CNA)
Linux Linuxb4d4efd4e351593c81e9293d4b4408d244fa5ee7Vendor (CNA)
Linux Linuxe4236bf3ec8d6bb15d0d8d825dcf9933a7d6666bVendor (CNA)
debian:linux6.1.176-1 · 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.

  • CVE-2025-38352362 days apartposix-cpu-timers: fix race between handle_posix_cpu_timers() and posix_cpu_timer_del()KEV
    61This week
  • CVE-2026-640340 days apartnet: mana: Fix TOCTOU double-fetch of hwc_msg_id from DMA buffer
    37Monitor
  • CVE-2026-641120 days apartrbd: eliminate a race in lock_dwork draining on unmap
    31Monitor
  • CVE-2026-5314524 days apartdrm/gem: Try to fix change_handle ioctl, attempt 4
    31Monitor
  • CVE-2026-5325024 days apartxsk: cache csum_start/csum_offset to fix TOCTOU in xsk_skb_metadata()
    31Monitor
  • CVE-2026-4343372 days apartrust_binder: avoid reading the written value in offsets array
    31Monitor

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).

Technical details

Attack conditions

  • Anyone who can reach it over the internet 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
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-367 · Time-of-check Time-of-use (TOCTOU) Race Condition

CVSS vector

CVSS:3.1/AV:N/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.

ATT&CK techniques

—

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