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NVD / CVE Program· CNA Linux

CVE-2025-38177: sch_hfsc: make hfsc_qlen_notify() idempotent

Noroxi assessment

Priority: Monitor (action score 22/100)

  • 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: 0.21% (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 0475c85426b18eccdcb7f9fb58d8f8e9c6c58c87, 51eb3b65544c9efd6a1026889ee5fb5aa62da3bb, 72c61ffbeeb8c50f6d4d70c65d3283aa1bac57a7; cbl2 kernel 5.15.186.1-1 on CBL Mariner 2.0 5.15.200.1-1.
  • Severity is disputed: the assigning authority (CNA) scores it 7.8, NVD 5.5.

Low priority for now. Upgrade to Linux Linux 0475c85426b18eccdcb7f9fb58d8f8e9c6c58c87, 51eb3b65544c9efd6a1026889ee5fb5aa62da3bb, 72c61ffbeeb8c50f6d4d70c65d3283aa1bac57a7; cbl2 kernel 5.15.186.1-1 on CBL Mariner 2.0 5.15.200.1-1 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: sch_hfsc: make hfsc_qlen_notify() idempotent hfsc_qlen_notify() is not idempotent either and not friendly to its callers, like fq_codel_dequeue(). Let's make it idempotent to ease qdisc_tree_reduce_backlog() callers' life: 1. update_vf() decreases cl->cl_nactive, so we can check whether it is non-zero before calling it. 2. eltree_remove() always removes RB node cl->el_node, but we can use RB_EMPTY_NODE() + RB_CLEAR_NODE() to make it safe.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Jul 4, 2025
Updated
Aug 5, 2026
EPSS
0.2% · 11th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 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
5.5
CNA · Linux
7.8
2.3 point gap

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

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-2025-38177

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
debiandebian linux

Affected versions

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

  • debian debian linux11.0
  • linux linux kernel5.5 and later · before 5.10.241
  • linux linux kernel5.11 and later · before 5.15.190
  • linux linux kernel5.16 and later · before 6.1.138
  • linux linux kernelbefore 5.4.297
  • linux linux kernel6.7 and later · before 6.12.28
  • linux linux kernel6.13 and later · before 6.14.6
  • linux linux kernel6.2 and later · before 6.6.90
  • linux linux kernel6.15

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

    • 4.14affected
    • 959466588aa7f84ccf79ae36a1d89542eaf9aaec and later · before 9a5fd5c2f4d4afdd5e405083ee53e0789ce76956affected · git
    • 959466588aa7f84ccf79ae36a1d89542eaf9aaec and later · before 72c61ffbeeb8c50f6d4d70c65d3283aa1bac57a7affected · git
    • 959466588aa7f84ccf79ae36a1d89542eaf9aaec and later · before a5efc95a33bd4fcb879250852828cc58c7862970affected · git
    • 959466588aa7f84ccf79ae36a1d89542eaf9aaec and later · before 0475c85426b18eccdcb7f9fb58d8f8e9c6c58c87affected · git
    • 959466588aa7f84ccf79ae36a1d89542eaf9aaec and later · before 9030a91235ae4845ec71902c3e0cecfc9ed1f2dfaffected · git
    • 959466588aa7f84ccf79ae36a1d89542eaf9aaec and later · before d06476714d2819b550e0cc39222347e2c8941c9daffected · git
    • 959466588aa7f84ccf79ae36a1d89542eaf9aaec and later · before c1175c4ad01dbc9c979d099861fa90a754f72059affected · git
    • 959466588aa7f84ccf79ae36a1d89542eaf9aaec and later · before 51eb3b65544c9efd6a1026889ee5fb5aa62da3bbaffected · git
    • before 4.14not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.139-16.1.139-1
Debian:13linuxbefore 6.12.29-16.12.29-1
Red Hat:rhel_aus:7.7::serverbpftoolbefore 0:3.10.0-1062.99.1.el70:3.10.0-1062.99.1.el7
Red Hat:rhel_aus:7.7::serverbpftool-debuginfobefore 0:3.10.0-1062.99.1.el70:3.10.0-1062.99.1.el7
Red Hat:rhel_aus:7.7::serverkernelbefore 0:3.10.0-1062.99.1.el70:3.10.0-1062.99.1.el7
Red Hat:rhel_aus:7.7::serverkernel-abi-whitelistsbefore 0:3.10.0-1062.99.1.el70:3.10.0-1062.99.1.el7
Red Hat:rhel_aus:7.7::serverkernel-debugbefore 0:3.10.0-1062.99.1.el70:3.10.0-1062.99.1.el7
Red Hat:rhel_aus:7.7::serverkernel-debug-debuginfobefore 0:3.10.0-1062.99.1.el70:3.10.0-1062.99.1.el7
Red Hat:rhel_aus:7.7::serverkernel-debug-develbefore 0:3.10.0-1062.99.1.el70:3.10.0-1062.99.1.el7
Red Hat:rhel_aus:7.7::serverkernel-debuginfobefore 0:3.10.0-1062.99.1.el70:3.10.0-1062.99.1.el7
Red Hat:rhel_aus:7.7::serverkernel-debuginfo-common-x86_64before 0:3.10.0-1062.99.1.el70:3.10.0-1062.99.1.el7
Red Hat:rhel_aus:7.7::serverkernel-develbefore 0:3.10.0-1062.99.1.el70:3.10.0-1062.99.1.el7
Red Hat:rhel_aus:7.7::serverkernel-docbefore 0:3.10.0-1062.99.1.el70:3.10.0-1062.99.1.el7
Red Hat:rhel_aus:7.7::serverkernel-toolsbefore 0:3.10.0-1062.99.1.el70:3.10.0-1062.99.1.el7
Red Hat:rhel_aus:7.7::serverkernel-tools-debuginfobefore 0:3.10.0-1062.99.1.el70:3.10.0-1062.99.1.el7
Red Hat:rhel_aus:7.7::serverkernel-tools-libsbefore 0:3.10.0-1062.99.1.el70:3.10.0-1062.99.1.el7
Red Hat:rhel_aus:7.7::serverkernel-tools-libs-develbefore 0:3.10.0-1062.99.1.el70:3.10.0-1062.99.1.el7
Red Hat:rhel_aus:7.7::serverperfbefore 0:3.10.0-1062.99.1.el70:3.10.0-1062.99.1.el7
Red Hat:rhel_aus:7.7::serverperf-debuginfobefore 0:3.10.0-1062.99.1.el70:3.10.0-1062.99.1.el7
Red Hat:rhel_aus:7.7::serverpython-perfbefore 0:3.10.0-1062.99.1.el70:3.10.0-1062.99.1.el7
Red Hat:rhel_aus:7.7::serverpython-perf-debuginfobefore 0:3.10.0-1062.99.1.el70:3.10.0-1062.99.1.el7
Red Hat:rhel_aus:8.2::baseosbpftoolbefore 0:4.18.0-193.165.1.el8_20:4.18.0-193.165.1.el8_2
Red Hat:rhel_aus:8.2::baseosbpftool-debuginfobefore 0:4.18.0-193.165.1.el8_20:4.18.0-193.165.1.el8_2
Red Hat:rhel_aus:8.2::baseoskernelbefore 0:4.18.0-193.165.1.el8_20:4.18.0-193.165.1.el8_2

+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-2025-38175Jul 4, 2025 · binder: fix yet another UAF in binder_devices
    31Monitor
  • ← EarlierCVE-2025-38176Jul 4, 2025 · binder: fix use-after-free in binderfs_evict_inode()
    31Monitor
  • Later →CVE-2025-38179Jul 4, 2025 · smb: client: fix max_sge overflow in smb_extract_folioq_to_rdma()
    31Monitor

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 Linux0475c85426b18eccdcb7f9fb58d8f8e9c6c58c87Vendor (CNA)
Linux Linux51eb3b65544c9efd6a1026889ee5fb5aa62da3bbVendor (CNA)
Linux Linux72c61ffbeeb8c50f6d4d70c65d3283aa1bac57a7Vendor (CNA)
Linux Linux9030a91235ae4845ec71902c3e0cecfc9ed1f2dfVendor (CNA)
Linux Linux9a5fd5c2f4d4afdd5e405083ee53e0789ce76956Vendor (CNA)
Linux Linuxa5efc95a33bd4fcb879250852828cc58c7862970Vendor (CNA)
Linux Linuxc1175c4ad01dbc9c979d099861fa90a754f72059Vendor (CNA)
Linux Linuxd06476714d2819b550e0cc39222347e2c8941c9dVendor (CNA)
cbl2 kernel 5.15.186.1-1 on CBL Mariner 2.05.15.200.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.1.139-1 · Debian:12Package registry (OSV)
red hat:bpftool0:3.10.0-1062.99.1.el7 · Red Hat:rhel_aus:7.7::serverPackage registry (OSV)
red hat:bpftool-debuginfo0:3.10.0-1062.99.1.el7 · Red Hat:rhel_aus:7.7::serverPackage registry (OSV)
red hat:kernel0:3.10.0-1062.99.1.el7 · Red Hat:rhel_aus:7.7::serverPackage registry (OSV)
red hat:kernel-abi-whitelists0:3.10.0-1062.99.1.el7 · Red Hat:rhel_aus:7.7::serverPackage registry (OSV)
red hat:kernel-debug0:3.10.0-1062.99.1.el7 · Red Hat:rhel_aus:7.7::serverPackage registry (OSV)
red hat:kernel-debug-debuginfo0:3.10.0-1062.99.1.el7 · Red Hat:rhel_aus:7.7::serverPackage registry (OSV)
red hat:kernel-debug-devel0:3.10.0-1062.99.1.el7 · Red Hat:rhel_aus:7.7::serverPackage registry (OSV)
red hat:kernel-debuginfo0:3.10.0-1062.99.1.el7 · Red Hat:rhel_aus:7.7::serverPackage registry (OSV)
red hat:kernel-debuginfo-common-x86_640:3.10.0-1062.99.1.el7 · Red Hat:rhel_aus:7.7::serverPackage registry (OSV)
red hat:kernel-devel0:3.10.0-1062.99.1.el7 · Red Hat:rhel_aus:7.7::serverPackage registry (OSV)
red hat:kernel-doc0:3.10.0-1062.99.1.el7 · Red Hat:rhel_aus:7.7::serverPackage registry (OSV)
red hat:kernel-tools0:3.10.0-1062.99.1.el7 · Red Hat:rhel_aus:7.7::serverPackage registry (OSV)
suse:kernel-64kb5.3.18-150300.59.215.1 · SUSE:Linux Enterprise Server 15 SP3-LTSSPackage registry (OSV)
suse:kernel-default5.3.18-150300.59.215.1 · SUSE:Linux Enterprise Live Patching 15 SP3Package registry (OSV)
suse:kernel-default-base5.3.18-150300.59.215.1.150300.18.128.1 · SUSE:Linux Enterprise Server 15 SP3-LTSSPackage registry (OSV)
suse:kernel-docs5.3.18-150300.59.215.1 · SUSE:Linux Enterprise Server 15 SP3-LTSSPackage registry (OSV)
suse:kernel-livepatch-SLE15-SP3_Update_601-150300.7.3.1 · SUSE:Linux Enterprise Live Patching 15 SP3Package registry (OSV)
suse:kernel-livepatch-SLE15-SP4_Update_431-150400.9.3.1 · SUSE:Linux Enterprise Live Patching 15 SP4Package registry (OSV)
suse:kernel-obs-build5.3.18-150300.59.215.1 · SUSE:Linux Enterprise Server 15 SP3-LTSSPackage registry (OSV)
suse:kernel-preempt5.3.18-150300.59.215.1 · SUSE:Linux Enterprise Server 15 SP3-LTSSPackage registry (OSV)

+4

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-2026-31668294 days apartseg6: separate dst_cache for input and output paths in seg6 lwtunnel
    39Monitor
  • CVE-2025-3790845 days apartmm, slab: clean up slab->obj_exts always
    31Monitor
  • CVE-2021-47110476 days apartx86/kvm: Disable kvmclock on all CPUs on shutdown
    28Monitor
  • CVE-2024-47693256 days apartIB/core: Fix ib_cache_setup_one error flow cleanup
    26Monitor
  • CVE-2025-2192494 days apartnet: hns3: make sure ptp clock is unregister and freed if hclge_ptp_get_cycle returns an error
    22Monitor
  • CVE-2023-5292999 days apartnvmem: core: fix cleanup after dev_set_name()
    22Monitor

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
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-459 · Incomplete Cleanup

CVSS vector

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

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 (9 more)

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

All records