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NVD / CVE Program· CNA Linux

CVE-2026-23449: net/sched: teql: Fix double-free in teql_master_xmit

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: 0.13% (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 21c89a0a8de7eadad8d385645a95b3233f23130e, 4a233447b941db451ea5f5a0942cffd0f7f7eaae, 4e8ebc4c18ea8213d28e6cb867d18fcc67daca21.

Low priority for now. Upgrade to Linux Linux 21c89a0a8de7eadad8d385645a95b3233f23130e, 4a233447b941db451ea5f5a0942cffd0f7f7eaae, 4e8ebc4c18ea8213d28e6cb867d18fcc67daca21 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/sched: teql: Fix double-free in teql_master_xmit Whenever a TEQL devices has a lockless Qdisc as root, qdisc_reset should be called using the seq_lock to avoid racing with the datapath. Failure to do so may cause crashes like the following: [ 238.028993][ T318] BUG: KASAN: double-free in skb_release_data (net/core/skbuff.c:1139) [ 238.029328][ T318] Free of addr ffff88810c67ec00 by task poc_teql_uaf_ke/318 [ 238.029749][ T318] [ 238.029900][ T318] CPU: 3 UID: 0 PID: 318 Comm: poc_teql_ke Not tainted 7.0.0-rc3-00149-ge5b31d988a41 #704 PREEMPT(full) [ 238.029906][ T318] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 238.029910][ T318] Call Trace: [ 238.029913][ T318] <TASK> [ 238.029916][ T318] dump_stack_lvl (lib/dump_stack.c:122) [ 238.029928][ T318] print_report (mm/kasan/report.c:379 mm/kasan/report.c:482) [ 238.029940][ T318] ? skb_release_data (net/core/skbuff.c:1139) [ 238.029944][ T318] ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221) ... [ 238.029957][ T318] ? skb_release_data (net/core/skbuff.c:1139) [ 238.029969][ T318] kasan_report_invalid_free (mm/kasan/report.c:221 mm/kasan/report.c:563) [ 238.029979][ T318] ? skb_release_data (net/core/skbuff.c:1139) [ 238.029989][ T318] check_slab_allocation (mm/kasan/common.c:231) [ 238.029995][ T318] kmem_cache_free (mm/slub.c:2637 (discriminator 1) mm/slub.c:6168 (discriminator 1) mm/slub.c:6298 (discriminator 1)) [ 238.030004][ T318] skb_release_data (net/core/skbuff.c:1139) ... [ 238.030025][ T318] sk_skb_reason_drop (net/core/skbuff.c:1256) [ 238.030032][ T318] pfifo_fast_reset (./include/linux/ptr_ring.h:171 ./include/linux/ptr_ring.h:309 ./include/linux/skb_array.h:98 net/sched/sch_generic.c:827) [ 238.030039][ T318] ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221) ... [ 238.030054][ T318] qdisc_reset (net/sched/sch_generic.c:1034) [ 238.030062][ T318] teql_destroy (./include/linux/spinlock.h:395 net/sched/sch_teql.c:157) [ 238.030071][ T318] __qdisc_destroy (./include/net/pkt_sched.h:328 net/sched/sch_generic.c:1077) [ 238.030077][ T318] qdisc_graft (net/sched/sch_api.c:1062 net/sched/sch_api.c:1053 net/sched/sch_api.c:1159) [ 238.030089][ T318] ? __pfx_qdisc_graft (net/sched/sch_api.c:1091) [ 238.030095][ T318] ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221) [ 238.030102][ T318] ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221) [ 238.030106][ T318] ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221) [ 238.030114][ T318] tc_get_qdisc (net/sched/sch_api.c:1529 net/sched/sch_api.c:1556) ... [ 238.072958][ T318] Allocated by task 303 on cpu 5 at 238.026275s: [ 238.073392][ T318] kasan_save_stack (mm/kasan/common.c:58) [ 238.073884][ T318] kasan_save_track (mm/kasan/common.c:64 (discriminator 5) mm/kasan/common.c:79 (discriminator 5)) [ 238.074230][ T318] __kasan_slab_alloc (mm/kasan/common.c:369) [ 238.074578][ T318] kmem_cache_alloc_node_noprof (./include/linux/kasan.h:253 mm/slub.c:4542 mm/slub.c:4869 mm/slub.c:4921) [ 238.076091][ T318] kmalloc_reserve (net/core/skbuff.c:616 (discriminator 107)) [ 238.076450][ T318] __alloc_skb (net/core/skbuff.c:713) [ 238.076834][ T318] alloc_skb_with_frags (./include/linux/skbuff.h:1383 net/core/skbuff.c:6763) [ 238.077178][ T318] sock_alloc_send_pskb (net/core/sock.c:2997) [ 238.077520][ T318] packet_sendmsg (net/packet/af_packet.c:2926 net/packet/af_packet.c:3019 net/packet/af_packet.c:3108) [ 238.081469][ T318] [ 238.081870][ T318] Freed by task 299 on cpu 1 at 238.028496s: [ 238.082761][ T318] kasan_save_stack (mm/kasan/common.c:58) [ 238.083481][ T318] kasan_save_track (mm/kasan/common.c:64 (discriminator 5) mm/kasan/common.c:79 (discriminator 5)) [ 238.085348][ T318] kasan_save_free_info (mm/kasan/generic.c:587 (discriminator 1)) [ 238.085900][ T318] __kasan_slab_free (mm/ ---truncated---

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Apr 3, 2026
Updated
Oct 19, 2026
EPSS
0.1% · 3th 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 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
7.8
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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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 kernel4.18 and later · before 6.1.167
  • linux linux kernel6.2 and later · before 6.6.130
  • linux linux kernel6.7 and later · before 6.12.78
  • linux linux kernel6.13 and later · before 6.18.20
  • linux linux kernel6.19 and later · before 6.19.10
  • linux linux kernel7.0

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

    • 4.18affected
    • 96009c7d500efdd5534e83b2e3eb2c58d4b137ae and later · before 4e8ebc4c18ea8213d28e6cb867d18fcc67daca21affected · git
    • 96009c7d500efdd5534e83b2e3eb2c58d4b137ae and later · before 21c89a0a8de7eadad8d385645a95b3233f23130eaffected · git
    • 96009c7d500efdd5534e83b2e3eb2c58d4b137ae and later · before afbc79a7770b230a9f24bd39271209d6b3682c5faffected · git
    • 96009c7d500efdd5534e83b2e3eb2c58d4b137ae and later · before e9c66d3e7d8557b3308e55c613aa07254fe97611affected · git
    • 96009c7d500efdd5534e83b2e3eb2c58d4b137ae and later · before 4a233447b941db451ea5f5a0942cffd0f7f7eaaeaffected · git
    • 96009c7d500efdd5534e83b2e3eb2c58d4b137ae and later · before 66360460cab63c248ca5b1070a01c0c29133b960affected · git
    • before 4.18not affected · semver
    • 6.1.167 and later · up to and including 6.1.*not affected · semver
    • 6.6.130 and later · up to and including 6.6.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.170-16.1.170-1
Debian:13linuxbefore 6.12.85-16.12.85-1
Debian:14linuxbefore 6.19.10-16.19.10-1
SUSE:Linux Enterprise Live Patching 12 SP5kgraft-patch-SLE12-SP5_Update_71before 17-2.117-2.1
SUSE:Linux Enterprise Live Patching 12 SP5kgraft-patch-SLE12-SP5_Update_72before 16-2.116-2.1
SUSE:Linux Enterprise Live Patching 12 SP5kgraft-patch-SLE12-SP5_Update_75before 12-2.112-2.1
SUSE:Linux Enterprise Live Patching 12 SP5kgraft-patch-SLE12-SP5_Update_76before 12-2.112-2.1
SUSE:Linux Enterprise Live Patching 12 SP5kgraft-patch-SLE12-SP5_Update_79before 8-2.18-2.1
SUSE:Linux Enterprise Live Patching 15 SP4kernel-livepatch-SLE15-SP4_Update_42before 22-150400.2.122-150400.2.1
SUSE:Linux Enterprise Live Patching 15 SP4kernel-livepatch-SLE15-SP4_Update_43before 19-150400.2.119-150400.2.1
SUSE:Linux Enterprise Live Patching 15 SP4kernel-livepatch-SLE15-SP4_Update_45before 16-150400.2.116-150400.2.1
SUSE:Linux Enterprise Live Patching 15 SP4kernel-livepatch-SLE15-SP4_Update_46before 12-150400.2.112-150400.2.1
SUSE:Linux Enterprise Live Patching 15 SP4kernel-livepatch-SLE15-SP4_Update_48before 10-150400.2.110-150400.2.1
SUSE:Linux Enterprise Live Patching 15 SP4kernel-livepatch-SLE15-SP4_Update_49before 8-150400.2.18-150400.2.1
SUSE:Linux Enterprise Live Patching 15 SP4kernel-livepatch-SLE15-SP4_Update_50before 8-150400.2.18-150400.2.1
SUSE:Linux Enterprise Live Patching 15 SP4kernel-livepatch-SLE15-SP4_Update_52before 6-150400.2.16-150400.2.1
SUSE:Linux Enterprise Live Patching 15 SP4kernel-livepatch-SLE15-SP4_Update_53before 5-150400.2.15-150400.2.1
SUSE:Linux Enterprise Live Patching 15 SP5kernel-livepatch-SLE15-SP5_Update_29before 20-150500.2.120-150500.2.1
SUSE:Linux Enterprise Live Patching 15 SP5kernel-livepatch-SLE15-SP5_Update_30before 17-150500.2.117-150500.2.1
SUSE:Linux Enterprise Live Patching 15 SP5kernel-livepatch-SLE15-SP5_Update_32before 12-150500.2.112-150500.2.1
SUSE:Linux Enterprise Live Patching 15 SP5kernel-livepatch-SLE15-SP5_Update_34before 12-150500.2.112-150500.2.1
SUSE:Linux Enterprise Live Patching 15 SP5kernel-livepatch-SLE15-SP5_Update_36before 8-150500.2.18-150500.2.1
SUSE:Linux Enterprise Live Patching 15 SP5kernel-livepatch-SLE15-SP5_Update_38before 7-150500.2.17-150500.2.1
SUSE:Linux Enterprise Live Patching 15 SP5kernel-livepatch-SLE15-SP5_Update_39before 6-150500.2.16-150500.2.1

+70

Same product

linux: all records

Other highest-scoring records for the same primary product.

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  • 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-2026-23445Apr 3, 2026 · igc: fix page fault in XDP TX timestamps handling
    22Monitor
  • ← EarlierCVE-2026-23446Apr 3, 2026 · net: usb: aqc111: Do not perform PM inside suspend callback
    22Monitor
  • Later →CVE-2026-23450Apr 3, 2026 · net/smc: fix NULL dereference and UAF in smc_tcp_syn_recv_sock()
    39Monitor

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 Linux21c89a0a8de7eadad8d385645a95b3233f23130eVendor (CNA)
Linux Linux4a233447b941db451ea5f5a0942cffd0f7f7eaaeVendor (CNA)
Linux Linux4e8ebc4c18ea8213d28e6cb867d18fcc67daca21Vendor (CNA)
Linux Linux66360460cab63c248ca5b1070a01c0c29133b960Vendor (CNA)
Linux Linuxafbc79a7770b230a9f24bd39271209d6b3682c5fVendor (CNA)
Linux Linuxe9c66d3e7d8557b3308e55c613aa07254fe97611Vendor (CNA)
debian:linux6.1.170-1 · Debian:12Package registry (OSV)
suse:kernel-livepatch-SLE16-RT_Update_015-160000.3.4 · SUSE:Linux Micro 6.2Package registry (OSV)
suse:kernel-livepatch-SLE16-RT_Update_114-160000.1.1 · SUSE:Linux Micro 6.2Package registry (OSV)
suse:kernel-livepatch-SLE16-RT_Update_106-160000.1.1 · SUSE:Linux Micro 6.2Package registry (OSV)
suse:kernel-livepatch-SLE16-RT_Update_116-160000.1.1 · SUSE:Linux Micro 6.2Package registry (OSV)
suse:kernel-livepatch-SLE16-RT_Update_212-160000.1.1 · SUSE:Linux Micro 6.2Package registry (OSV)
suse:kernel-livepatch-SLE16-RT_Update_311-160000.1.1 · SUSE:Linux Micro 6.2Package registry (OSV)
suse:kernel-livepatch-SLE16-RT_Update_411-160000.1.1 · SUSE:Linux Micro 6.2Package registry (OSV)
suse:kernel-livepatch-SLE16-RT_Update_510-160000.1.1 · SUSE:Linux Micro 6.2Package registry (OSV)
suse:kernel-livepatch-SLE16-RT_Update_69-160000.1.1 · SUSE:Linux Micro 6.2Package registry (OSV)
suse:kernel-livepatch-SLE16-RT_Update_78-160000.1.1 · SUSE:Linux Micro 6.2Package registry (OSV)
suse:kernel-livepatch-SLE16-RT_Update_87-160000.1.1 · SUSE:Linux Micro 6.2Package registry (OSV)
suse:kernel-livepatch-SLE16-RT_Update_96-160000.1.1 · SUSE:Linux Micro 6.2Package 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.

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.

  • CVE-2026-3160821 days apartsmb: server: avoid double-free in smb_direct_free_sendmsg after smb_direct_flush_send_list()
    39Monitor
  • CVE-2026-3160921 days apartsmb: client: avoid double-free in smbd_free_send_io() after smbd_send_batch_flush()
    39Monitor
  • CVE-2026-4301128 days apartnet/x25: Fix potential double free of skb
    39Monitor
  • CVE-2026-4341435 days apartscsi: qla2xxx: Completely fix fcport double free
    39Monitor
  • CVE-2026-5299382 days aparttipc: fix double-free in tipc_buf_append()
    39Monitor
  • CVE-2026-63888107 days apartscsi: target: iscsi: Fix CRC overread and double-free in iscsit_handle_text_cmd()
    39Monitor

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-415 · Double Free

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/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. SSVC exploitation— → none
  2. Fix✗ → ✓

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

References

Show all references (8 more)

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

All records