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NVD / CVE Program· CNA Linux

CVE-2025-21692: net: sched: fix ets qdisc OOB Indexing

Noroxi assessment

Priority: Monitor (action score 31/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.61% (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 03c56665dab1f4ac844bc156652d50d639093fa5, 1332c6ed446be787f901ed1064ec6a3c694f028a, 997f6ec4208b23c87daf9f044689685f091826f7; azl3 kernel 6.6.64.2-9 on Azure Linux 3.0 6.6.76.1-1; azl3 kernel 6.6.76.1-1 on Azure Linux 3.0 6.6.76.1-1.

Low priority for now. Upgrade to Linux Linux 03c56665dab1f4ac844bc156652d50d639093fa5, 1332c6ed446be787f901ed1064ec6a3c694f028a, 997f6ec4208b23c87daf9f044689685f091826f7; azl3 kernel 6.6.64.2-9 on Azure Linux 3.0 6.6.76.1-1; azl3 kernel 6.6.76.1-1 on Azure Linux 3.0 6.6.76.1-1 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: fix ets qdisc OOB Indexing Haowei Yan <g1042620637@gmail.com> found that ets_class_from_arg() can index an Out-Of-Bound class in ets_class_from_arg() when passed clid of 0. The overflow may cause local privilege escalation. [ 18.852298] ------------[ cut here ]------------ [ 18.853271] UBSAN: array-index-out-of-bounds in net/sched/sch_ets.c:93:20 [ 18.853743] index 18446744073709551615 is out of range for type 'ets_class [16]' [ 18.854254] CPU: 0 UID: 0 PID: 1275 Comm: poc Not tainted 6.12.6-dirty #17 [ 18.854821] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 [ 18.856532] Call Trace: [ 18.857441] <TASK> [ 18.858227] dump_stack_lvl+0xc2/0xf0 [ 18.859607] dump_stack+0x10/0x20 [ 18.860908] __ubsan_handle_out_of_bounds+0xa7/0xf0 [ 18.864022] ets_class_change+0x3d6/0x3f0 [ 18.864322] tc_ctl_tclass+0x251/0x910 [ 18.864587] ? lock_acquire+0x5e/0x140 [ 18.865113] ? __mutex_lock+0x9c/0xe70 [ 18.866009] ? __mutex_lock+0xa34/0xe70 [ 18.866401] rtnetlink_rcv_msg+0x170/0x6f0 [ 18.866806] ? __lock_acquire+0x578/0xc10 [ 18.867184] ? __pfx_rtnetlink_rcv_msg+0x10/0x10 [ 18.867503] netlink_rcv_skb+0x59/0x110 [ 18.867776] rtnetlink_rcv+0x15/0x30 [ 18.868159] netlink_unicast+0x1c3/0x2b0 [ 18.868440] netlink_sendmsg+0x239/0x4b0 [ 18.868721] ____sys_sendmsg+0x3e2/0x410 [ 18.869012] ___sys_sendmsg+0x88/0xe0 [ 18.869276] ? rseq_ip_fixup+0x198/0x260 [ 18.869563] ? rseq_update_cpu_node_id+0x10a/0x190 [ 18.869900] ? trace_hardirqs_off+0x5a/0xd0 [ 18.870196] ? syscall_exit_to_user_mode+0xcc/0x220 [ 18.870547] ? do_syscall_64+0x93/0x150 [ 18.870821] ? __memcg_slab_free_hook+0x69/0x290 [ 18.871157] __sys_sendmsg+0x69/0xd0 [ 18.871416] __x64_sys_sendmsg+0x1d/0x30 [ 18.871699] x64_sys_call+0x9e2/0x2670 [ 18.871979] do_syscall_64+0x87/0x150 [ 18.873280] ? do_syscall_64+0x93/0x150 [ 18.874742] ? lock_release+0x7b/0x160 [ 18.876157] ? do_user_addr_fault+0x5ce/0x8f0 [ 18.877833] ? irqentry_exit_to_user_mode+0xc2/0x210 [ 18.879608] ? irqentry_exit+0x77/0xb0 [ 18.879808] ? clear_bhb_loop+0x15/0x70 [ 18.880023] ? clear_bhb_loop+0x15/0x70 [ 18.880223] ? clear_bhb_loop+0x15/0x70 [ 18.880426] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 18.880683] RIP: 0033:0x44a957 [ 18.880851] Code: ff ff e8 fc 00 00 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 8974 24 10 [ 18.881766] RSP: 002b:00007ffcdd00fad8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 18.882149] RAX: ffffffffffffffda RBX: 00007ffcdd010db8 RCX: 000000000044a957 [ 18.882507] RDX: 0000000000000000 RSI: 00007ffcdd00fb70 RDI: 0000000000000003 [ 18.885037] RBP: 00007ffcdd010bc0 R08: 000000000703c770 R09: 000000000703c7c0 [ 18.887203] R10: 0000000000000080 R11: 0000000000000246 R12: 0000000000000001 [ 18.888026] R13: 00007ffcdd010da8 R14: 00000000004ca7d0 R15: 0000000000000001 [ 18.888395] </TASK> [ 18.888610] ---[ end trace ]---

HighCVSS 7.8 · v3.1—Proof of concept Fix available
Published
Feb 10, 2025
Updated
Oct 15, 2026
EPSS
0.6% · 49th 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 · 0.6%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

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
  • Proof of concept exists, no weaponized module
  • A fix has been released

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

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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 kernel5.6 and later · before 5.10.234
  • linux linux kernel5.11 and later · before 5.15.178
  • linux linux kernel5.16 and later · before 6.1.128
  • linux linux kernel6.2 and later · before 6.6.75
  • linux linux kernel6.7 and later · before 6.12.12
  • linux linux kernel6.13

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

    • 5.6affected
    • dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33 and later · before 03c56665dab1f4ac844bc156652d50d639093fa5affected · git
    • dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33 and later · before bcf0d815e728a3a304b50455b32a3170c16e1eaaaffected · git
    • dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33 and later · before 1332c6ed446be787f901ed1064ec6a3c694f028aaffected · git
    • dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33 and later · before f4168299e553f17aa2ba4016e77a9c38da40eb1daffected · git
    • dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33 and later · before 997f6ec4208b23c87daf9f044689685f091826f7affected · git
    • dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33 and later · before f6b0f05fbfa4044f890e8a348288c0d9a20bd1d0affected · git
    • dcc68b4d8084e1ac9af0d4022d6b1aff6a139a33 and later · before d62b04fca4340a0d468d7853bd66e511935a18cbaffected · git
    • before 5.6not affected · semver
    • 5.10.234 and later · up to and including 5.10.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.128-16.1.128-1
Debian:13linuxbefore 6.12.12-16.12.12-1
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSkernel-64kbbefore 5.3.18-150300.59.198.15.3.18-150300.59.198.1
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSkernel-default-basebefore 5.3.18-150300.59.198.1.150300.18.118.15.3.18-150300.59.198.1.150300.18.118.1
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSkernel-docsbefore 5.3.18-150300.59.198.15.3.18-150300.59.198.1
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSkernel-obs-buildbefore 5.3.18-150300.59.198.15.3.18-150300.59.198.1
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSkernel-preemptbefore 5.3.18-150300.59.198.15.3.18-150300.59.198.1
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSkernel-sourcebefore 5.3.18-150300.59.198.15.3.18-150300.59.198.1
SUSE:Linux Enterprise High Performance Computing 15 SP3-LTSSkernel-symsbefore 5.3.18-150300.59.198.15.3.18-150300.59.198.1
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSkernel-64kbbefore 5.14.21-150400.24.153.15.14.21-150400.24.153.1
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSkernel-docsbefore 5.14.21-150400.24.153.15.14.21-150400.24.153.1
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSkernel-obs-buildbefore 5.14.21-150400.24.153.15.14.21-150400.24.153.1
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSkernel-sourcebefore 5.14.21-150400.24.153.15.14.21-150400.24.153.1
SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOSkernel-symsbefore 5.14.21-150400.24.153.15.14.21-150400.24.153.1
SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOSkernel-64kbbefore 5.14.21-150500.55.97.15.14.21-150500.55.97.1
SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOSkernel-docsbefore 5.14.21-150500.55.97.15.14.21-150500.55.97.1
SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOSkernel-obs-buildbefore 5.14.21-150500.55.97.15.14.21-150500.55.97.1
SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOSkernel-symsbefore 5.14.21-150500.55.97.15.14.21-150500.55.97.1
SUSE:Linux Enterprise Live Patching 15 SP3kernel-defaultbefore 5.3.18-150300.59.198.15.3.18-150300.59.198.1
SUSE:Linux Enterprise Live Patching 15 SP3kernel-livepatch-SLE15-SP3_Update_48before 18-150300.2.118-150300.2.1
SUSE:Linux Enterprise Live Patching 15 SP3kernel-livepatch-SLE15-SP3_Update_49before 17-150300.2.117-150300.2.1
SUSE:Linux Enterprise Live Patching 15 SP3kernel-livepatch-SLE15-SP3_Update_50before 15-150300.2.115-150300.2.1
SUSE:Linux Enterprise Live Patching 15 SP3kernel-livepatch-SLE15-SP3_Update_51before 13-150300.2.113-150300.2.1
SUSE:Linux Enterprise Live Patching 15 SP3kernel-livepatch-SLE15-SP3_Update_52before 12-150300.2.112-150300.2.1

+39

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-2025-21691Feb 10, 2025 · cachestat: fix page cache statistics permission checking
    22Monitor
  • ← EarlierCVE-2025-21693Feb 10, 2025 · mm: zswap: properly synchronize freeing resources during CPU hotunplug
    31Monitor
  • Later →CVE-2024-57952Feb 12, 2025 · Revert "libfs: fix infinite directory reads for offset dir"
    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 Linux03c56665dab1f4ac844bc156652d50d639093fa5Vendor (CNA)
Linux Linux1332c6ed446be787f901ed1064ec6a3c694f028aVendor (CNA)
Linux Linux997f6ec4208b23c87daf9f044689685f091826f7Vendor (CNA)
Linux Linuxbcf0d815e728a3a304b50455b32a3170c16e1eaaVendor (CNA)
Linux Linuxd62b04fca4340a0d468d7853bd66e511935a18cbVendor (CNA)
Linux Linuxf4168299e553f17aa2ba4016e77a9c38da40eb1dVendor (CNA)
Linux Linuxf6b0f05fbfa4044f890e8a348288c0d9a20bd1d0Vendor (CNA)
azl3 kernel 6.6.64.2-9 on Azure Linux 3.06.6.76.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 kernel 6.6.76.1-1 on Azure Linux 3.06.6.76.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.176.3-3 on CBL Mariner 2.05.15.180.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.176.3-3 on CBL-Mariner 2.05.15.180.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.180.1-1 on CBL Mariner 2.05.15.180.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.1.128-1 · Debian:12Package registry (OSV)
suse:kernel-livepatch-SLE15-SP3_Update_4818-150300.2.1 · SUSE:Linux Enterprise Live Patching 15 SP3Package registry (OSV)
suse:kernel-livepatch-SLE15-SP3_Update_5015-150300.2.1 · SUSE:Linux Enterprise Live Patching 15 SP3Package registry (OSV)
suse:kernel-livepatch-SLE15-SP3_Update_5113-150300.2.1 · SUSE:Linux Enterprise Live Patching 15 SP3Package registry (OSV)
suse:kernel-livepatch-SLE15-SP3_Update_5212-150300.2.1 · SUSE:Linux Enterprise Live Patching 15 SP3Package registry (OSV)
suse:kernel-livepatch-SLE15-SP3_Update_549-150300.2.1 · SUSE:Linux Enterprise Live Patching 15 SP3Package registry (OSV)
suse:kernel-livepatch-SLE15-SP4_Update_3315-150400.2.1 · SUSE:Linux Enterprise Live Patching 15 SP4Package registry (OSV)
suse:kernel-livepatch-SLE15-SP4_Update_3414-150400.2.1 · SUSE:Linux Enterprise Live Patching 15 SP4Package registry (OSV)
suse:kernel-livepatch-SLE15-SP6-RT_Update_218-150600.2.1 · SUSE:Linux Enterprise Live Patching 15 SP6Package registry (OSV)
suse:kernel-livepatch-SLE15-SP6-RT_Update_318-150600.2.1 · SUSE:Linux Enterprise Live Patching 15 SP6Package registry (OSV)
suse:kernel-livepatch-SLE15-SP6-RT_Update_417-150600.2.1 · SUSE:Linux Enterprise Live Patching 15 SP6Package registry (OSV)
suse:kernel-livepatch-SLE15-SP6-RT_Update_613-150600.2.1 · SUSE:Linux Enterprise Live Patching 15 SP6Package registry (OSV)
suse:kernel-livepatch-SLE15-SP6-RT_Update_713-150600.2.1 · SUSE:Linux Enterprise Live Patching 15 SP6Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:402025-09-13

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.

  1. Published
  2. First PoC+214 d
  3. TodayNov 9, 2026+637 d

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-2021-47548262 days apartethernet: hisilicon: hns: hns_dsaf_misc: fix a possible array overflow in hns_dsaf_ge_srst_by_port()
    39Monitor
  • CVE-2026-64018524 days apartnet: mana: validate rx_req_idx to prevent out-of-bounds array access
    37Monitor
  • CVE-2026-23246401 days apartwifi: mac80211: bounds-check link_id in ieee80211_ml_reconfiguration
    35Monitor
  • CVE-2026-43110450 days apartwifi: brcmfmac: validate bsscfg indices in IF events
    35Monitor
  • CVE-2026-43172450 days apartwifi: iwlwifi: fix 22000 series SMEM parsing
    35Monitor
  • CVE-2025-2168010 days apartpktgen: Avoid out-of-bounds access in get_imix_entries
    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

  • 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-129 · Improper Validation of Array Index

CVSS vector

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

nvd-primary

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 (10 more)

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

All records