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NVD / CVE Program· CNA Linux

CVE-2026-53223: net: guard timestamp cmsgs to real error queue skbs

Noroxi assessment

Priority: Monitor (action score 28/100)

  • 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 1ee90b77b727df903033db873c75caac5c27ec98, 24a0d548d3a765cd4558224e4f8e06e14cba26e3, 3dde4fb941fa5649ab809f6cd3e20e0c424a4e31; azl3 kernel 6.6.139.1-1 on Azure Linux 3.0 6.6.143.1-1.

Low priority for now. Upgrade to Linux Linux 1ee90b77b727df903033db873c75caac5c27ec98, 24a0d548d3a765cd4558224e4f8e06e14cba26e3, 3dde4fb941fa5649ab809f6cd3e20e0c424a4e31; azl3 kernel 6.6.139.1-1 on Azure Linux 3.0 6.6.143.1-1 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: guard timestamp cmsgs to real error queue skbs skb_is_err_queue() treats PACKET_OUTGOING as the sole marker for an skb from sk_error_queue. That assumption is not true for AF_PACKET sockets: outgoing packet taps are also delivered to packet sockets with skb->pkt_type == PACKET_OUTGOING, but their skb->cb is owned by AF_PACKET instead of struct sock_exterr_skb. If such an skb is received with timestamping enabled, the generic timestamp cmsg path can read AF_PACKET control-buffer state as sock_exterr_skb::opt_stats. With SO_RXQ_OVFL enabled, the packet drop counter overlaps opt_stats. An odd drop count makes the path emit SCM_TIMESTAMPING_OPT_STATS with skb->len and skb->data. For non-linear skbs this copies past the linear head and can trigger hardened usercopy or disclose adjacent heap contents. Keep skb_is_err_queue() local to net/socket.c, but make it verify that the PACKET_OUTGOING marker is paired with the sock_rmem_free destructor installed by sock_queue_err_skb(). AF_PACKET receive skbs use normal receive ownership and no longer pass as error-queue skbs, while legitimate sk_error_queue entries keep the PACKET_OUTGOING marker and sock_rmem_free ownership.

HighCVSS 7.1 · v3.1—No exploit Fix available
Published
Jun 25, 2026
Updated
Oct 19, 2026
EPSS
0.1% · 3th percentile

Report tools

JSON

Action score

28

Monitor

Low priority for now.

CVSS
28 / 40 · 7.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
7.1
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 kernel4.10.14 and later · before 4.11
  • linux linux kernel4.11.1 and later · before 5.10.259
  • linux linux kernel5.11 and later · before 5.15.210
  • linux linux kernel5.16 and later · before 6.1.176
  • linux linux kernel6.2 and later · before 6.6.143
  • linux linux kernel6.7 and later · before 6.12.94
  • linux linux kernel6.13 and later · before 6.18.36
  • linux linux kernel6.19 and later · before 7.0.13
  • linux linux kernel4.11
  • linux linux kernel7.1

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

    • cdaf15b43bd31003220cb080bcbbd57787a2fca9, 4.11affected
    • 8605330aac5a5785630aec8f64378a54891937cc and later · before 24a0d548d3a765cd4558224e4f8e06e14cba26e3affected · git
    • 8605330aac5a5785630aec8f64378a54891937cc and later · before 71ff5cdd5da61d0438e902aa0fd68c28bc901abeaffected · git
    • 8605330aac5a5785630aec8f64378a54891937cc and later · before ad9a0374ee6d11048e1f74cd5180bad58b9848b4affected · git
    • 8605330aac5a5785630aec8f64378a54891937cc and later · before b903e9b5629ec8dd6db92174070045bf81ad7060affected · git
    • 8605330aac5a5785630aec8f64378a54891937cc and later · before e0665b2a8e90bb08bd205062c75662b502d31797affected · git
    • 8605330aac5a5785630aec8f64378a54891937cc and later · before 3dde4fb941fa5649ab809f6cd3e20e0c424a4e31affected · git
    • 8605330aac5a5785630aec8f64378a54891937cc and later · before eb51a9ad3ceb01bc6c0fb608dbc856e03ee6f24aaffected · git
    • 8605330aac5a5785630aec8f64378a54891937cc and later · before 1ee90b77b727df903033db873c75caac5c27ec98affected · git
    • 4.10.14 and later · before 4.11affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:8bpftoolbefore 4.18.0-553.164.1.el8_104.18.0-553.164.1.el8_10
AlmaLinux:8kernelbefore 4.18.0-553.164.1.el8_104.18.0-553.164.1.el8_10
AlmaLinux:8kernel-abi-stablelistsbefore 4.18.0-553.164.1.el8_104.18.0-553.164.1.el8_10
AlmaLinux:8kernel-corebefore 4.18.0-553.164.1.el8_104.18.0-553.164.1.el8_10
AlmaLinux:8kernel-cross-headersbefore 4.18.0-553.164.1.el8_104.18.0-553.164.1.el8_10
AlmaLinux:8kernel-debugbefore 4.18.0-553.164.1.el8_104.18.0-553.164.1.el8_10
AlmaLinux:8kernel-debug-corebefore 4.18.0-553.164.1.el8_104.18.0-553.164.1.el8_10
AlmaLinux:8kernel-debug-develbefore 4.18.0-553.164.1.el8_104.18.0-553.164.1.el8_10
AlmaLinux:8kernel-debug-modulesbefore 4.18.0-553.164.1.el8_104.18.0-553.164.1.el8_10
AlmaLinux:8kernel-debug-modules-extrabefore 4.18.0-553.164.1.el8_104.18.0-553.164.1.el8_10
AlmaLinux:8kernel-develbefore 4.18.0-553.164.1.el8_104.18.0-553.164.1.el8_10
AlmaLinux:8kernel-docbefore 4.18.0-553.164.1.el8_104.18.0-553.164.1.el8_10
AlmaLinux:8kernel-headersbefore 4.18.0-553.164.1.el8_104.18.0-553.164.1.el8_10
AlmaLinux:8kernel-modulesbefore 4.18.0-553.164.1.el8_104.18.0-553.164.1.el8_10
AlmaLinux:8kernel-modules-extrabefore 4.18.0-553.164.1.el8_104.18.0-553.164.1.el8_10
AlmaLinux:8kernel-rtbefore 4.18.0-553.164.1.rt7.505.el8_104.18.0-553.164.1.rt7.505.el8_10
AlmaLinux:8kernel-rt-corebefore 4.18.0-553.164.1.rt7.505.el8_104.18.0-553.164.1.rt7.505.el8_10
AlmaLinux:8kernel-rt-debugbefore 4.18.0-553.164.1.rt7.505.el8_104.18.0-553.164.1.rt7.505.el8_10
AlmaLinux:8kernel-rt-debug-corebefore 4.18.0-553.164.1.rt7.505.el8_104.18.0-553.164.1.rt7.505.el8_10
AlmaLinux:8kernel-rt-debug-develbefore 4.18.0-553.164.1.rt7.505.el8_104.18.0-553.164.1.rt7.505.el8_10
AlmaLinux:8kernel-rt-debug-modulesbefore 4.18.0-553.164.1.rt7.505.el8_104.18.0-553.164.1.rt7.505.el8_10
AlmaLinux:8kernel-rt-debug-modules-extrabefore 4.18.0-553.164.1.rt7.505.el8_104.18.0-553.164.1.rt7.505.el8_10
AlmaLinux:8kernel-rt-develbefore 4.18.0-553.164.1.rt7.505.el8_104.18.0-553.164.1.rt7.505.el8_10
AlmaLinux:8kernel-rt-modulesbefore 4.18.0-553.164.1.rt7.505.el8_104.18.0-553.164.1.rt7.505.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-2026-53221Jun 25, 2026 · ip6_vti: fix incorrect tunnel matching in vti6_tnl_lookup()
    39Monitor
  • ← EarlierCVE-2026-53222Jun 25, 2026 · ptp: ocp: fix resource freeing order
    22Monitor
  • Later →CVE-2026-53224Jun 25, 2026 · sctp: validate embedded INIT chunk and address list lengths in cookie
    36Monitor

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 Linux1ee90b77b727df903033db873c75caac5c27ec98Vendor (CNA)
Linux Linux24a0d548d3a765cd4558224e4f8e06e14cba26e3Vendor (CNA)
Linux Linux3dde4fb941fa5649ab809f6cd3e20e0c424a4e31Vendor (CNA)
Linux Linux4.11Vendor (CNA)
Linux Linux71ff5cdd5da61d0438e902aa0fd68c28bc901abeVendor (CNA)
Linux Linuxad9a0374ee6d11048e1f74cd5180bad58b9848b4Vendor (CNA)
Linux Linuxb903e9b5629ec8dd6db92174070045bf81ad7060Vendor (CNA)
Linux Linuxe0665b2a8e90bb08bd205062c75662b502d31797Vendor (CNA)
Linux Linuxeb51a9ad3ceb01bc6c0fb608dbc856e03ee6f24aVendor (CNA)
azl3 kernel 6.6.139.1-1 on Azure Linux 3.06.6.143.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
almalinux:kernel5.14.0-687.46.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k5.14.0-687.46.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-core5.14.0-687.46.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug5.14.0-687.46.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-core5.14.0-687.46.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-devel5.14.0-687.46.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-devel-matched5.14.0-687.46.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules5.14.0-687.46.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules-core5.14.0-687.46.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules-extra5.14.0-687.46.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-devel5.14.0-687.46.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-devel-matched5.14.0-687.46.1.el9_8 · AlmaLinux:9Package registry (OSV)
debian:linux6.1.176-1 · Debian:12Package registry (OSV)
red hat:kernel-64k-debug-debuginfo0:6.12.0-211.52.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debug-devel0:6.12.0-211.52.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debug-devel-matched0:6.12.0-211.52.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debuginfo0:6.12.0-211.52.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-devel0:6.12.0-211.52.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-devel-matched0:6.12.0-211.52.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debug-debuginfo0:6.12.0-211.52.1.el10_2 · Red Hat:enterprise_linux:10.2Package 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
none
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
None
Availability impact
High

Weakness class (CWE)

CWE-125 · Out-of-bounds Read

CVSS vector

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

ATT&CK techniques

—

Change log

  1. SSVC exploitation— → none
  2. 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