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NVD / CVE Program· CNA Linux

CVE-2026-74436: rxrpc: serialize kernel accept preallocation with socket teardown

Noroxi assessment

Priority: Monitor (action score 39/100)

  • 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: 0.39% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: Linux Linux 0337cdba0c477f176c0459bed012109453184573, 11b429b84c87cb5a0152f14e7d6cb649ed363901, 1741378a7a83dfd8e53a9196730df709b903cd33.

Low priority for now. Upgrade to Linux Linux 0337cdba0c477f176c0459bed012109453184573, 11b429b84c87cb5a0152f14e7d6cb649ed363901, 1741378a7a83dfd8e53a9196730df709b903cd33 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: rxrpc: serialize kernel accept preallocation with socket teardown rxrpc_kernel_charge_accept() reads rx->backlog without any socket/backlog synchronization and passes that raw pointer into rxrpc_service_prealloc_one(). A concurrent rxrpc_discard_prealloc() sets rx->backlog = NULL and frees the backlog rings, so a kernel preallocation worker can keep using a freed struct rxrpc_backlog while updating *_backlog_head/tail and array slots. Serialize the state check and backlog lookup with the socket lock, and reject kernel preallocation once teardown has disabled listening or discarded the service backlog.

CriticalCVSS 9.8 · v3.1—No exploit Fix available
Published
Aug 15, 2026
Updated
Oct 16, 2026
EPSS
0.3% · 34th percentile
CWE
—

Report tools

JSON

Action score

39

Monitor

Low priority for now.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
9.8
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.

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-2026-74436

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

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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.

—

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

    • 4.9affected
    • 00e907127e6f86d0f9b122d9b4347a8aa09a8b61 and later · before d6207326b4ca0ae1041281b6af9df53f8080669aaffected · git
    • 00e907127e6f86d0f9b122d9b4347a8aa09a8b61 and later · before 11b429b84c87cb5a0152f14e7d6cb649ed363901affected · git
    • 00e907127e6f86d0f9b122d9b4347a8aa09a8b61 and later · before c20d983968f239574290cf804a58cde18ad1c559affected · git
    • 00e907127e6f86d0f9b122d9b4347a8aa09a8b61 and later · before 0337cdba0c477f176c0459bed012109453184573affected · git
    • 00e907127e6f86d0f9b122d9b4347a8aa09a8b61 and later · before dfa0b2bbc5e50119f89c6b5407faa5ed86dfa7c5affected · git
    • 00e907127e6f86d0f9b122d9b4347a8aa09a8b61 and later · before 35a967ff8b24db09ee429c39c5b5e6571639997daffected · git
    • 00e907127e6f86d0f9b122d9b4347a8aa09a8b61 and later · before 1741378a7a83dfd8e53a9196730df709b903cd33affected · git
    • 00e907127e6f86d0f9b122d9b4347a8aa09a8b61 and later · before dc175389b18c29a5303ee83169ec653adfae3e17affected · git
    • before 4.9not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.187-16.1.187-1
Debian:12linux-6.12before 6.12.101-1~deb12u16.12.101-1~deb12u1
Debian:13linuxbefore 6.12.101-16.12.101-1
Debian:14linuxbefore 7.1.5-17.1.5-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-74427Aug 15, 2026 · afs: Fix netns teardown to cancel the preallocation charger
    39Monitor
  • ← EarlierCVE-2026-74432Aug 15, 2026 · rxrpc: Fix leak of released call in recvmsg(MSG_PEEK)
    0Monitor
  • Later →CVE-2026-74439Aug 15, 2026 · iommu/vt-d: Clear Present bit before tearing down scalable-mode context entry
    37Monitor

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 Linux0337cdba0c477f176c0459bed012109453184573Vendor (CNA)
Linux Linux11b429b84c87cb5a0152f14e7d6cb649ed363901Vendor (CNA)
Linux Linux1741378a7a83dfd8e53a9196730df709b903cd33Vendor (CNA)
Linux Linux35a967ff8b24db09ee429c39c5b5e6571639997dVendor (CNA)
Linux Linuxc20d983968f239574290cf804a58cde18ad1c559Vendor (CNA)
Linux Linuxd6207326b4ca0ae1041281b6af9df53f8080669aVendor (CNA)
Linux Linuxdc175389b18c29a5303ee83169ec653adfae3e17Vendor (CNA)
Linux Linuxdfa0b2bbc5e50119f89c6b5407faa5ed86dfa7c5Vendor (CNA)
debian:linux6.1.187-1 · Debian:12Package registry (OSV)
debian:linux-6.126.12.101-1~deb12u1 · Debian:12Package registry (OSV)

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.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

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

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • 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
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

—

CVSS vector

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

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

Change log

  1. SSVC exploitation— → none
  2. Fix✗ → ✓

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

References

Show all references (7 more)

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

All records