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NVD / CVE Program· CNA Linux

CVE-2024-36979: net: bridge: mst: fix vlan use-after-free

Noroxi assessment

Priority: Monitor (action score 31/100)

  • 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: 0.25% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 3a7c1661ae1383364cd6092d851f5e5da64d476b, 4488617e5e995a09abe4d81add5fb165674edb59, 8ca9a750fc711911ef616ceb627d07357b04545e.

Low priority for now. Upgrade to Linux Linux 3a7c1661ae1383364cd6092d851f5e5da64d476b, 4488617e5e995a09abe4d81add5fb165674edb59, 8ca9a750fc711911ef616ceb627d07357b04545e 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: net: bridge: mst: fix vlan use-after-free syzbot reported a suspicious rcu usage[1] in bridge's mst code. While fixing it I noticed that nothing prevents a vlan to be freed while walking the list from the same path (br forward delay timer). Fix the rcu usage and also make sure we are not accessing freed memory by making br_mst_vlan_set_state use rcu read lock. [1] WARNING: suspicious RCU usage 6.9.0-rc6-syzkaller #0 Not tainted ----------------------------- net/bridge/br_private.h:1599 suspicious rcu_dereference_protected() usage! ... stack backtrace: CPU: 1 PID: 8017 Comm: syz-executor.1 Not tainted 6.9.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 lockdep_rcu_suspicious+0x221/0x340 kernel/locking/lockdep.c:6712 nbp_vlan_group net/bridge/br_private.h:1599 [inline] br_mst_set_state+0x1ea/0x650 net/bridge/br_mst.c:105 br_set_state+0x28a/0x7b0 net/bridge/br_stp.c:47 br_forward_delay_timer_expired+0x176/0x440 net/bridge/br_stp_timer.c:88 call_timer_fn+0x18e/0x650 kernel/time/timer.c:1793 expire_timers kernel/time/timer.c:1844 [inline] __run_timers kernel/time/timer.c:2418 [inline] __run_timer_base+0x66a/0x8e0 kernel/time/timer.c:2429 run_timer_base kernel/time/timer.c:2438 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2448 __do_softirq+0x2c6/0x980 kernel/softirq.c:554 invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf2/0x1c0 kernel/softirq.c:633 irq_exit_rcu+0x9/0x30 kernel/softirq.c:645 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5758 Code: 2b 00 74 08 4c 89 f7 e8 ba d1 84 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc90013657100 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920026cae2c RCX: 0000000000000001 RDX: dffffc0000000000 RSI: ffffffff8bcaca00 RDI: ffffffff8c1eaa60 RBP: ffffc90013657260 R08: ffffffff92efe507 R09: 1ffffffff25dfca0 R10: dffffc0000000000 R11: fffffbfff25dfca1 R12: 1ffff920026cae28 R13: dffffc0000000000 R14: ffffc90013657160 R15: 0000000000000246

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Jun 19, 2024
Updated
Aug 5, 2026
EPSS
0.2% · 17th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
7.8
CNA · Linux
7.8
agree

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-2024-36979

When you'll hear from us

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  • 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 kernel5.18 and later · before 6.1.93
  • linux linux kernel6.2 and later · before 6.6.33
  • linux linux kernel6.7 and later · before 6.8.12
  • linux linux kernel6.9 and later · before 6.9.3

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

    • 5.18affected
    • ec7328b59176227216c461601c6bd0e922232a9b and later · before 8ca9a750fc711911ef616ceb627d07357b04545eaffected · git
    • ec7328b59176227216c461601c6bd0e922232a9b and later · before 4488617e5e995a09abe4d81add5fb165674edb59affected · git
    • ec7328b59176227216c461601c6bd0e922232a9b and later · before a2b01e65d9ba8af2bb086d3b7288ca53a07249acaffected · git
    • ec7328b59176227216c461601c6bd0e922232a9b and later · before e43dd2b1ec746e105b7db5f9ad6ef14685a615a4affected · git
    • ec7328b59176227216c461601c6bd0e922232a9b and later · before 3a7c1661ae1383364cd6092d851f5e5da64d476baffected · git
    • before 5.18not affected · semver
    • 6.1.93 and later · up to and including 6.1.*not affected · semver
    • 6.6.33 and later · up to and including 6.6.*not affected · semver
    • 6.8.12 and later · up to and including 6.8.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:9bpftoolbefore 7.3.0-427.35.1.el9_47.3.0-427.35.1.el9_4
AlmaLinux:9kernelbefore 5.14.0-427.35.1.el9_45.14.0-427.35.1.el9_4
AlmaLinux:9kernel-64kbefore 5.14.0-427.35.1.el9_45.14.0-427.35.1.el9_4
AlmaLinux:9kernel-64k-corebefore 5.14.0-427.35.1.el9_45.14.0-427.35.1.el9_4
AlmaLinux:9kernel-64k-debugbefore 5.14.0-427.35.1.el9_45.14.0-427.35.1.el9_4
AlmaLinux:9kernel-64k-debug-corebefore 5.14.0-427.35.1.el9_45.14.0-427.35.1.el9_4
AlmaLinux:9kernel-64k-debug-develbefore 5.14.0-427.35.1.el9_45.14.0-427.35.1.el9_4
AlmaLinux:9kernel-64k-debug-devel-matchedbefore 5.14.0-427.35.1.el9_45.14.0-427.35.1.el9_4
AlmaLinux:9kernel-64k-debug-modulesbefore 5.14.0-427.35.1.el9_45.14.0-427.35.1.el9_4
AlmaLinux:9kernel-64k-debug-modules-corebefore 5.14.0-427.35.1.el9_45.14.0-427.35.1.el9_4
AlmaLinux:9kernel-64k-debug-modules-extrabefore 5.14.0-427.35.1.el9_45.14.0-427.35.1.el9_4
AlmaLinux:9kernel-64k-develbefore 5.14.0-427.35.1.el9_45.14.0-427.35.1.el9_4
AlmaLinux:9kernel-64k-devel-matchedbefore 5.14.0-427.35.1.el9_45.14.0-427.35.1.el9_4
AlmaLinux:9kernel-64k-modulesbefore 5.14.0-427.35.1.el9_45.14.0-427.35.1.el9_4
AlmaLinux:9kernel-64k-modules-corebefore 5.14.0-427.35.1.el9_45.14.0-427.35.1.el9_4
AlmaLinux:9kernel-64k-modules-extrabefore 5.14.0-427.35.1.el9_45.14.0-427.35.1.el9_4
AlmaLinux:9kernel-abi-stablelistsbefore 5.14.0-427.35.1.el9_45.14.0-427.35.1.el9_4
AlmaLinux:9kernel-corebefore 5.14.0-427.35.1.el9_45.14.0-427.35.1.el9_4
AlmaLinux:9kernel-cross-headersbefore 5.14.0-427.35.1.el9_45.14.0-427.35.1.el9_4
AlmaLinux:9kernel-debugbefore 5.14.0-427.35.1.el9_45.14.0-427.35.1.el9_4
AlmaLinux:9kernel-debug-corebefore 5.14.0-427.35.1.el9_45.14.0-427.35.1.el9_4
AlmaLinux:9kernel-debug-develbefore 5.14.0-427.35.1.el9_45.14.0-427.35.1.el9_4
AlmaLinux:9kernel-debug-devel-matchedbefore 5.14.0-427.35.1.el9_45.14.0-427.35.1.el9_4
AlmaLinux:9kernel-debug-modulesbefore 5.14.0-427.35.1.el9_45.14.0-427.35.1.el9_4

+96

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • 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

Published before and after this one in the same product

  • ← EarlierCVE-2024-36974Jun 18, 2024 · net/sched: taprio: always validate TCA_TAPRIO_ATTR_PRIOMAP
    31Monitor
  • ← EarlierCVE-2024-36978Jun 19, 2024 · net: sched: sch_multiq: fix possible OOB write in multiq_tune()
    31Monitor
  • Later →CVE-2024-38538Jun 19, 2024 · net: bridge: xmit: make sure we have at least eth header len bytes
    28Monitor

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 Linux3a7c1661ae1383364cd6092d851f5e5da64d476bVendor (CNA)
Linux Linux4488617e5e995a09abe4d81add5fb165674edb59Vendor (CNA)
Linux Linux8ca9a750fc711911ef616ceb627d07357b04545eVendor (CNA)
Linux Linuxa2b01e65d9ba8af2bb086d3b7288ca53a07249acVendor (CNA)
Linux Linuxe43dd2b1ec746e105b7db5f9ad6ef14685a615a4Vendor (CNA)
almalinux:bpftool7.3.0-427.35.1.el9_4 · AlmaLinux:9Package registry (OSV)
almalinux:kernel5.14.0-427.35.1.el9_4 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k5.14.0-427.35.1.el9_4 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-core5.14.0-427.35.1.el9_4 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug5.14.0-427.35.1.el9_4 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-core5.14.0-427.35.1.el9_4 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-devel5.14.0-427.35.1.el9_4 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-devel-matched5.14.0-427.35.1.el9_4 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules5.14.0-427.35.1.el9_4 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules-core5.14.0-427.35.1.el9_4 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules-extra5.14.0-427.35.1.el9_4 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-devel5.14.0-427.35.1.el9_4 · AlmaLinux:9Package registry (OSV)
debian:linux6.1.94-1 · Debian:12Package registry (OSV)
red hat:bpftool-debuginfo0:7.3.0-427.35.1.el9_4 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-debug-debuginfo0:5.14.0-427.35.1.el9_4 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-debug-devel0:5.14.0-427.35.1.el9_4 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-debug-devel-matched0:5.14.0-427.35.1.el9_4 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-debuginfo0:5.14.0-427.35.1.el9_4 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-devel0:5.14.0-427.35.1.el9_4 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-devel-matched0:5.14.0-427.35.1.el9_4 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debug-debuginfo0:5.14.0-427.35.1.el9_4 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debug-devel0:5.14.0-427.35.1.el9_4 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debug-devel-matched0:5.14.0-427.35.1.el9_4 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debuginfo0:5.14.0-427.35.1.el9_4 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debuginfo-common-aarch640:5.14.0-427.35.1.el9_4 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)

+7

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.

No history yet (it accumulates with the daily EPSS job).

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).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • 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
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

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

nvd-primary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

c
free(dev->buf);/* ... another thread is still running ... */process(dev->buf);

Fixed

c
lock(&dev->lock);free(dev->buf);dev->buf = NULL;unlock(&dev->lock);

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 (4 more)

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

All records