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NVD / CVE Program· CNA Linux

CVE-2024-26923: af_unix: Fix garbage collector racing against connect()

Noroxi assessment

Priority: Monitor (action score 18/100)

  • 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: 0.20% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: Linux Linux 2e2a03787f4f0abc0072350654ab0ef3324d9db3, 343c5372d5e17b306db5f8f3c895539b06e3177f, 47d8ac011fe1c9251070e1bd64cb10b48193ec51.
  • Severity is disputed: the assigning authority (CNA) scores it 7.8, NVD 4.7.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 2e2a03787f4f0abc0072350654ab0ef3324d9db3, 343c5372d5e17b306db5f8f3c895539b06e3177f, 47d8ac011fe1c9251070e1bd64cb10b48193ec51 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: af_unix: Fix garbage collector racing against connect() Garbage collector does not take into account the risk of embryo getting enqueued during the garbage collection. If such embryo has a peer that carries SCM_RIGHTS, two consecutive passes of scan_children() may see a different set of children. Leading to an incorrectly elevated inflight count, and then a dangling pointer within the gc_inflight_list. sockets are AF_UNIX/SOCK_STREAM S is an unconnected socket L is a listening in-flight socket bound to addr, not in fdtable V's fd will be passed via sendmsg(), gets inflight count bumped connect(S, addr) sendmsg(S, [V]); close(V) __unix_gc() ---------------- ------------------------- ----------- NS = unix_create1() skb1 = sock_wmalloc(NS) L = unix_find_other(addr) unix_state_lock(L) unix_peer(S) = NS // V count=1 inflight=0 NS = unix_peer(S) skb2 = sock_alloc() skb_queue_tail(NS, skb2[V]) // V became in-flight // V count=2 inflight=1 close(V) // V count=1 inflight=1 // GC candidate condition met for u in gc_inflight_list: if (total_refs == inflight_refs) add u to gc_candidates // gc_candidates={L, V} for u in gc_candidates: scan_children(u, dec_inflight) // embryo (skb1) was not // reachable from L yet, so V's // inflight remains unchanged __skb_queue_tail(L, skb1) unix_state_unlock(L) for u in gc_candidates: if (u.inflight) scan_children(u, inc_inflight_move_tail) // V count=1 inflight=2 (!) If there is a GC-candidate listening socket, lock/unlock its state. This makes GC wait until the end of any ongoing connect() to that socket. After flipping the lock, a possibly SCM-laden embryo is already enqueued. And if there is another embryo coming, it can not possibly carry SCM_RIGHTS. At this point, unix_inflight() can not happen because unix_gc_lock is already taken. Inflight graph remains unaffected.

MediumCVSS 4.7 · v3.1—No exploit Fix available
Published
Apr 25, 2024
Updated
Nov 3, 2026
EPSS
0.2% · 10th percentile

Report tools

JSON

Action score

18

Monitor

Low priority for now.

CVSS
18 / 40 · 4.7 / 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
4.7
CNA · Linux
7.8
3.1 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.

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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 linux10.0
  • linux linux kernel4.20 and later · before 5.4.275
  • linux linux kernel5.5 and later · before 5.10.216
  • linux linux kernel5.11 and later · before 5.15.156
  • linux linux kernel2.6.23 and later · before 4.19.314
  • linux linux kernel6.2 and later · before 6.6.28
  • linux linux kernel6.7 and later · before 6.8.7
  • linux linux kernel5.16 and later · before 6.1.87
  • linux linux kernel6.9

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

    • 2.6.23affected
    • 1fd05ba5a2f2aa8e7b9b52ef55df850e2e7d54c9 and later · before a36ae0ec2353015f0f6762e59f4c2dbc0c906423affected · git
    • 1fd05ba5a2f2aa8e7b9b52ef55df850e2e7d54c9 and later · before 343c5372d5e17b306db5f8f3c895539b06e3177faffected · git
    • 1fd05ba5a2f2aa8e7b9b52ef55df850e2e7d54c9 and later · before 2e2a03787f4f0abc0072350654ab0ef3324d9db3affected · git
    • 1fd05ba5a2f2aa8e7b9b52ef55df850e2e7d54c9 and later · before e76c2678228f6aec74b305ae30c9374cc2f28a51affected · git
    • 1fd05ba5a2f2aa8e7b9b52ef55df850e2e7d54c9 and later · before b75722be422c276b699200de90527d01c602ea7caffected · git
    • 1fd05ba5a2f2aa8e7b9b52ef55df850e2e7d54c9 and later · before 507cc232ffe53a352847893f8177d276c3b532a9affected · git
    • 1fd05ba5a2f2aa8e7b9b52ef55df850e2e7d54c9 and later · before dbdf7bec5c920200077d693193f989cb1513f009affected · git
    • 1fd05ba5a2f2aa8e7b9b52ef55df850e2e7d54c9 and later · before 47d8ac011fe1c9251070e1bd64cb10b48193ec51affected · git
    • before 2.6.23not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:9bpftoolbefore 7.3.0-427.42.1.el9_47.3.0-427.42.1.el9_4
AlmaLinux:9kernelbefore 5.14.0-427.42.1.el9_45.14.0-427.42.1.el9_4
AlmaLinux:9kernel-64kbefore 5.14.0-427.42.1.el9_45.14.0-427.42.1.el9_4
AlmaLinux:9kernel-64k-corebefore 5.14.0-427.42.1.el9_45.14.0-427.42.1.el9_4
AlmaLinux:9kernel-64k-debugbefore 5.14.0-427.42.1.el9_45.14.0-427.42.1.el9_4
AlmaLinux:9kernel-64k-debug-corebefore 5.14.0-427.42.1.el9_45.14.0-427.42.1.el9_4
AlmaLinux:9kernel-64k-debug-develbefore 5.14.0-427.42.1.el9_45.14.0-427.42.1.el9_4
AlmaLinux:9kernel-64k-debug-devel-matchedbefore 5.14.0-427.42.1.el9_45.14.0-427.42.1.el9_4
AlmaLinux:9kernel-64k-debug-modulesbefore 5.14.0-427.42.1.el9_45.14.0-427.42.1.el9_4
AlmaLinux:9kernel-64k-debug-modules-corebefore 5.14.0-427.42.1.el9_45.14.0-427.42.1.el9_4
AlmaLinux:9kernel-64k-debug-modules-extrabefore 5.14.0-427.42.1.el9_45.14.0-427.42.1.el9_4
AlmaLinux:9kernel-64k-develbefore 5.14.0-427.42.1.el9_45.14.0-427.42.1.el9_4
AlmaLinux:9kernel-64k-devel-matchedbefore 5.14.0-427.42.1.el9_45.14.0-427.42.1.el9_4
AlmaLinux:9kernel-64k-modulesbefore 5.14.0-427.42.1.el9_45.14.0-427.42.1.el9_4
AlmaLinux:9kernel-64k-modules-corebefore 5.14.0-427.42.1.el9_45.14.0-427.42.1.el9_4
AlmaLinux:9kernel-64k-modules-extrabefore 5.14.0-427.42.1.el9_45.14.0-427.42.1.el9_4
AlmaLinux:9kernel-abi-stablelistsbefore 5.14.0-427.42.1.el9_45.14.0-427.42.1.el9_4
AlmaLinux:9kernel-corebefore 5.14.0-427.42.1.el9_45.14.0-427.42.1.el9_4
AlmaLinux:9kernel-cross-headersbefore 5.14.0-427.42.1.el9_45.14.0-427.42.1.el9_4
AlmaLinux:9kernel-debugbefore 5.14.0-427.42.1.el9_45.14.0-427.42.1.el9_4
AlmaLinux:9kernel-debug-corebefore 5.14.0-427.42.1.el9_45.14.0-427.42.1.el9_4
AlmaLinux:9kernel-debug-develbefore 5.14.0-427.42.1.el9_45.14.0-427.42.1.el9_4
AlmaLinux:9kernel-debug-devel-matchedbefore 5.14.0-427.42.1.el9_45.14.0-427.42.1.el9_4
AlmaLinux:9kernel-debug-modulesbefore 5.14.0-427.42.1.el9_45.14.0-427.42.1.el9_4

+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-2024-26924Apr 25, 2024 · netfilter: nft_set_pipapo: do not free live element
    31Monitor
  • ← EarlierCVE-2024-26926Apr 25, 2024 · binder: check offset alignment in binder_get_object()
    22Monitor
  • Later →CVE-2024-26925Apr 25, 2024 · netfilter: nf_tables: release mutex after nft_gc_seq_end from abort path
    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 Linux2e2a03787f4f0abc0072350654ab0ef3324d9db3Vendor (CNA)
Linux Linux343c5372d5e17b306db5f8f3c895539b06e3177fVendor (CNA)
Linux Linux47d8ac011fe1c9251070e1bd64cb10b48193ec51Vendor (CNA)
Linux Linux507cc232ffe53a352847893f8177d276c3b532a9Vendor (CNA)
Linux Linuxa36ae0ec2353015f0f6762e59f4c2dbc0c906423Vendor (CNA)
Linux Linuxb75722be422c276b699200de90527d01c602ea7cVendor (CNA)
Linux Linuxdbdf7bec5c920200077d693193f989cb1513f009Vendor (CNA)
Linux Linuxe76c2678228f6aec74b305ae30c9374cc2f28a51Vendor (CNA)
almalinux:bpftool7.3.0-427.42.1.el9_4 · AlmaLinux:9Package registry (OSV)
almalinux:kernel5.14.0-427.42.1.el9_4 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k5.14.0-427.42.1.el9_4 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-core5.14.0-427.42.1.el9_4 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug5.14.0-427.42.1.el9_4 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-core5.14.0-427.42.1.el9_4 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-devel5.14.0-427.42.1.el9_4 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-devel-matched5.14.0-427.42.1.el9_4 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules5.14.0-427.42.1.el9_4 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules-core5.14.0-427.42.1.el9_4 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules-extra5.14.0-427.42.1.el9_4 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-devel5.14.0-427.42.1.el9_4 · AlmaLinux:9Package registry (OSV)
debian:linux6.1.90-1 · Debian:12Package registry (OSV)
red hat:bpftool0:4.18.0-477.74.1.el8_8 · Red Hat:rhel_eus:8.8::baseosPackage registry (OSV)
red hat:bpftool-debuginfo0:4.18.0-477.74.1.el8_8 · Red Hat:rhel_eus:8.8::baseosPackage registry (OSV)
red hat:kernel0:4.18.0-477.74.1.el8_8 · Red Hat:rhel_eus:8.8::baseosPackage registry (OSV)
red hat:kernel-abi-stablelists0:4.18.0-477.74.1.el8_8 · Red Hat:rhel_eus:8.8::baseosPackage registry (OSV)
red hat:kernel-core0:4.18.0-477.74.1.el8_8 · Red Hat:rhel_eus:8.8::baseosPackage registry (OSV)
red hat:kernel-debug0:4.18.0-477.74.1.el8_8 · Red Hat:rhel_eus:8.8::baseosPackage registry (OSV)
red hat:kernel-debug-core0:4.18.0-477.74.1.el8_8 · Red Hat:rhel_eus:8.8::baseosPackage registry (OSV)
red hat:kernel-debug-debuginfo0:4.18.0-477.74.1.el8_8 · Red Hat:rhel_eus:8.8::baseosPackage registry (OSV)
red hat:kernel-debug-devel0:4.18.0-477.74.1.el8_8 · Red Hat:rhel_eus:8.8::baseosPackage registry (OSV)

+16

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).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

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.
  • Special conditions such as timing or configuration are required.

If successful

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

Weakness class (CWE)

CWE-362 · Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSS vector

CVSS:3.1/AV:L/AC:H/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.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

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

References

Show all references (12 more)

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

All records