Skip to content
Noroxi
NVD / CVE Program· CNA Linux

CVE-2025-21919: sched/fair: Fix potential memory corruption in child_cfs_rq_on_list

HighCVSS 7.8 · v3.1—No exploit Fix available

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: 0.23% (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 000c9ee43928f2ce68a156dd40bab7616256f4dd, 3b4035ddbfc8e4521f85569998a7569668cccf51, 5cb300dcdd27e6a351ac02541e0231261c775852; azl3 kernel 6.6.82.1-1 on Azure Linux 3.0 6.6.85.1-2; azl3 kernel 6.6.85.1-2 on Azure Linux 3.0 6.6.85.1-2.

Low priority for now. Upgrade to Linux Linux 000c9ee43928f2ce68a156dd40bab7616256f4dd, 3b4035ddbfc8e4521f85569998a7569668cccf51, 5cb300dcdd27e6a351ac02541e0231261c775852; azl3 kernel 6.6.82.1-1 on Azure Linux 3.0 6.6.85.1-2; azl3 kernel 6.6.85.1-2 on Azure Linux 3.0 6.6.85.1-2 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: sched/fair: Fix potential memory corruption in child_cfs_rq_on_list child_cfs_rq_on_list attempts to convert a 'prev' pointer to a cfs_rq. This 'prev' pointer can originate from struct rq's leaf_cfs_rq_list, making the conversion invalid and potentially leading to memory corruption. Depending on the relative positions of leaf_cfs_rq_list and the task group (tg) pointer within the struct, this can cause a memory fault or access garbage data. The issue arises in list_add_leaf_cfs_rq, where both cfs_rq->leaf_cfs_rq_list and rq->leaf_cfs_rq_list are added to the same leaf list. Also, rq->tmp_alone_branch can be set to rq->leaf_cfs_rq_list. This adds a check `if (prev == &rq->leaf_cfs_rq_list)` after the main conditional in child_cfs_rq_on_list. This ensures that the container_of operation will convert a correct cfs_rq struct. This check is sufficient because only cfs_rqs on the same CPU are added to the list, so verifying the 'prev' pointer against the current rq's list head is enough. Fixes a potential memory corruption issue that due to current struct layout might not be manifesting as a crash but could lead to unpredictable behavior when the layout changes.

Published
Apr 1, 2025
Updated
Nov 10, 2026
EPSS
0.2% · 14th 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
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
  • 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-2025-21919

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

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits every 10 minutes on paid plans, on the hour on the free plan.

Your free account also gets you

  • CVE alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools, at most 30 a day (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for linux records
Is your version affected? Check it

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.

We use this product, ask for help

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

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

    • 5.13affected
    • fdaba61ef8a268d4136d0a113d153f7a89eb9984 and later · before 5cb300dcdd27e6a351ac02541e0231261c775852affected · git
    • fdaba61ef8a268d4136d0a113d153f7a89eb9984 and later · before 000c9ee43928f2ce68a156dd40bab7616256f4ddaffected · git
    • fdaba61ef8a268d4136d0a113d153f7a89eb9984 and later · before 9cc7f0018609f75a349e42e3aebc3b0e905ba775affected · git
    • fdaba61ef8a268d4136d0a113d153f7a89eb9984 and later · before b5741e4b9ef3567613b2351384f91d3f16e59986affected · git
    • fdaba61ef8a268d4136d0a113d153f7a89eb9984 and later · before e1dd09df30ba86716cb2ffab97dc35195c01eb8faffected · git
    • fdaba61ef8a268d4136d0a113d153f7a89eb9984 and later · before 3b4035ddbfc8e4521f85569998a7569668cccf51affected · git
    • before 5.13not affected · semver
    • 5.15.179 and later · up to and including 5.15.*not affected · semver
    • 6.1.131 and later · up to and including 6.1.*not affected · semver
Affected versions · NVD (6)

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

  • linux linux kernel5.13 and later · before 5.15.179
  • linux linux kernel5.16 and later · before 6.1.131
  • linux linux kernel6.2 and later · before 6.6.83
  • linux linux kernel6.7 and later · before 6.12.19
  • linux linux kernel6.13 and later · before 6.13.7
  • linux linux kernel6.14

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:8bpftoolbefore 4.18.0-553.64.1.el8_104.18.0-553.64.1.el8_10
AlmaLinux:8kernelbefore 4.18.0-553.64.1.el8_104.18.0-553.64.1.el8_10
AlmaLinux:8kernel-abi-stablelistsbefore 4.18.0-553.64.1.el8_104.18.0-553.64.1.el8_10
AlmaLinux:8kernel-corebefore 4.18.0-553.64.1.el8_104.18.0-553.64.1.el8_10
AlmaLinux:8kernel-cross-headersbefore 4.18.0-553.64.1.el8_104.18.0-553.64.1.el8_10
AlmaLinux:8kernel-debugbefore 4.18.0-553.64.1.el8_104.18.0-553.64.1.el8_10
AlmaLinux:8kernel-debug-corebefore 4.18.0-553.64.1.el8_104.18.0-553.64.1.el8_10
AlmaLinux:8kernel-debug-develbefore 4.18.0-553.64.1.el8_104.18.0-553.64.1.el8_10
AlmaLinux:8kernel-debug-modulesbefore 4.18.0-553.64.1.el8_104.18.0-553.64.1.el8_10
AlmaLinux:8kernel-debug-modules-extrabefore 4.18.0-553.64.1.el8_104.18.0-553.64.1.el8_10
AlmaLinux:8kernel-develbefore 4.18.0-553.64.1.el8_104.18.0-553.64.1.el8_10
AlmaLinux:8kernel-docbefore 4.18.0-553.64.1.el8_104.18.0-553.64.1.el8_10
AlmaLinux:8kernel-headersbefore 4.18.0-553.64.1.el8_104.18.0-553.64.1.el8_10
AlmaLinux:8kernel-modulesbefore 4.18.0-553.64.1.el8_104.18.0-553.64.1.el8_10
AlmaLinux:8kernel-modules-extrabefore 4.18.0-553.64.1.el8_104.18.0-553.64.1.el8_10
AlmaLinux:8kernel-rtbefore 4.18.0-553.64.1.rt7.405.el8_104.18.0-553.64.1.rt7.405.el8_10
AlmaLinux:8kernel-rt-corebefore 4.18.0-553.64.1.rt7.405.el8_104.18.0-553.64.1.rt7.405.el8_10
AlmaLinux:8kernel-rt-debugbefore 4.18.0-553.64.1.rt7.405.el8_104.18.0-553.64.1.rt7.405.el8_10
AlmaLinux:8kernel-rt-debug-corebefore 4.18.0-553.64.1.rt7.405.el8_104.18.0-553.64.1.rt7.405.el8_10
AlmaLinux:8kernel-rt-debug-develbefore 4.18.0-553.64.1.rt7.405.el8_104.18.0-553.64.1.rt7.405.el8_10
AlmaLinux:8kernel-rt-debug-modulesbefore 4.18.0-553.64.1.rt7.405.el8_104.18.0-553.64.1.rt7.405.el8_10
AlmaLinux:8kernel-rt-debug-modules-extrabefore 4.18.0-553.64.1.rt7.405.el8_104.18.0-553.64.1.rt7.405.el8_10
AlmaLinux:8kernel-rt-develbefore 4.18.0-553.64.1.rt7.405.el8_104.18.0-553.64.1.rt7.405.el8_10
AlmaLinux:8kernel-rt-modulesbefore 4.18.0-553.64.1.rt7.405.el8_104.18.0-553.64.1.rt7.405.el8_10

+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-2025-21913Apr 1, 2025 · x86/amd_nb: Use rdmsr_safe() in amd_get_mmconfig_range()
    22Monitor
  • ← EarlierCVE-2025-21916Apr 1, 2025 · usb: atm: cxacru: fix a flaw in existing endpoint checks
    22Monitor
  • Later →CVE-2025-21921Apr 1, 2025 · net: ethtool: netlink: Allow NULL nlattrs when getting a phy_device
    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 Linux000c9ee43928f2ce68a156dd40bab7616256f4ddVendor (CNA)
Linux Linux3b4035ddbfc8e4521f85569998a7569668cccf51Vendor (CNA)
Linux Linux5cb300dcdd27e6a351ac02541e0231261c775852Vendor (CNA)
Linux Linux9cc7f0018609f75a349e42e3aebc3b0e905ba775Vendor (CNA)
Linux Linuxb5741e4b9ef3567613b2351384f91d3f16e59986Vendor (CNA)
Linux Linuxe1dd09df30ba86716cb2ffab97dc35195c01eb8fVendor (CNA)
azl3 kernel 6.6.82.1-1 on Azure Linux 3.06.6.85.1-2 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 kernel 6.6.85.1-2 on Azure Linux 3.06.6.85.1-2 · 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)
almalinux:bpftool4.18.0-553.64.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel4.18.0-553.64.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-abi-stablelists4.18.0-553.64.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-core4.18.0-553.64.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-cross-headers4.18.0-553.64.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug4.18.0-553.64.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-core4.18.0-553.64.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-devel4.18.0-553.64.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules4.18.0-553.64.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules-extra4.18.0-553.64.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-devel4.18.0-553.64.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-doc4.18.0-553.64.1.el8_10 · AlmaLinux:8Package registry (OSV)
debian:linux6.1.133-1 · Debian:12Package registry (OSV)
opensuse:dtb-aarch646.4.0-150600.23.53.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-64kb6.4.0-150600.23.53.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-azure6.4.0-150600.8.40.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-debug6.4.0-150600.23.53.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-default6.4.0-150600.23.53.1 · openSUSE:Leap 15.6Package registry (OSV)
opensuse:kernel-default-base6.4.0-150600.23.53.1.150600.12.24.1 · openSUSE:Leap 15.6Package registry (OSV)

+32

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.

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

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-787 · Out-of-bounds Write

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.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

References

Show all references (8 more)

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

All records