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NVD / CVE Program· CNA Linux

CVE-2022-50555: tipc: fix a null-ptr-deref in tipc_topsrv_accept

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: 0.22% (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 24b129aed8730e48f47d852d58d76825ab6f407c, 32a3d4660b34ce49ac0162338ebe362098e2f5df, 7a939503fc32bff4ed60800b73ff7fbb4aea2142.
  • Severity is disputed: the assigning authority (CNA) scores it 7.8, NVD 5.5.

Low priority for now. Upgrade to Linux Linux 24b129aed8730e48f47d852d58d76825ab6f407c, 32a3d4660b34ce49ac0162338ebe362098e2f5df, 7a939503fc32bff4ed60800b73ff7fbb4aea2142 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: tipc: fix a null-ptr-deref in tipc_topsrv_accept syzbot found a crash in tipc_topsrv_accept: KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] Workqueue: tipc_rcv tipc_topsrv_accept RIP: 0010:kernel_accept+0x22d/0x350 net/socket.c:3487 Call Trace: <TASK> tipc_topsrv_accept+0x197/0x280 net/tipc/topsrv.c:460 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 It was caused by srv->listener that might be set to null by tipc_topsrv_stop() in net .exit whereas it's still used in tipc_topsrv_accept() worker. srv->listener is protected by srv->idr_lock in tipc_topsrv_stop(), so add a check for srv->listener under srv->idr_lock in tipc_topsrv_accept() to avoid the null-ptr-deref. To ensure the lsock is not released during the tipc_topsrv_accept(), move sock_release() after tipc_topsrv_work_stop() where it's waiting until the tipc_topsrv_accept worker to be done. Note that sk_callback_lock is used to protect sk->sk_user_data instead of srv->listener, and it should check srv in tipc_topsrv_listener_data_ready() instead. This also ensures that no more tipc_topsrv_accept worker will be started after tipc_conn_close() is called in tipc_topsrv_stop() where it sets sk->sk_user_data to null.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Oct 7, 2025
Updated
Aug 5, 2026
EPSS
0.2% · 12th 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%

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.

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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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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

Affected versions

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

  • linux linux kernel4.17 and later · before 4.19.264
  • linux linux kernel4.20 and later · before 5.4.223
  • linux linux kernel5.5 and later · before 5.10.153
  • linux linux kernel5.11 and later · before 5.15.77
  • linux linux kernel5.16 and later · before 6.0.7
  • linux linux kernel6.1

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

    • 4.17affected
    • 0ef897be12b8b4cf297b6016e79ec97ec90f2cf6 and later · before ce69bdac2310152bb70845024d5d704c52aabfc3affected · git
    • 0ef897be12b8b4cf297b6016e79ec97ec90f2cf6 and later · before 24b129aed8730e48f47d852d58d76825ab6f407caffected · git
    • 0ef897be12b8b4cf297b6016e79ec97ec90f2cf6 and later · before 32a3d4660b34ce49ac0162338ebe362098e2f5dfaffected · git
    • 0ef897be12b8b4cf297b6016e79ec97ec90f2cf6 and later · before 7a939503fc32bff4ed60800b73ff7fbb4aea2142affected · git
    • 0ef897be12b8b4cf297b6016e79ec97ec90f2cf6 and later · before cedb41664e27b2cae7e21487f1bee22dcd84037daffected · git
    • 0ef897be12b8b4cf297b6016e79ec97ec90f2cf6 and later · before 82cb4e4612c633a9ce320e1773114875604a3cceaffected · git
    • before 4.17not affected · semver
    • 4.19.264 and later · up to and including 4.19.*not affected · semver
    • 5.4.223 and later · up to and including 5.4.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.0.7-16.0.7-1

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-2022-50553Oct 7, 2025 · tracing/hist: Fix out-of-bound write on 'action_data.var_ref_idx'
    22Monitor
  • ← EarlierCVE-2022-50554Oct 7, 2025 · blk-mq: avoid double ->queue_rq() because of early timeout
    22Monitor
  • Later →CVE-2023-53617Oct 7, 2025 · soc: aspeed: socinfo: Add kfree for kstrdup
    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 Linux24b129aed8730e48f47d852d58d76825ab6f407cVendor (CNA)
Linux Linux32a3d4660b34ce49ac0162338ebe362098e2f5dfVendor (CNA)
Linux Linux7a939503fc32bff4ed60800b73ff7fbb4aea2142Vendor (CNA)
Linux Linux82cb4e4612c633a9ce320e1773114875604a3cceVendor (CNA)
Linux Linuxce69bdac2310152bb70845024d5d704c52aabfc3Vendor (CNA)
Linux Linuxcedb41664e27b2cae7e21487f1bee22dcd84037dVendor (CNA)
debian:linux6.0.7-1 · 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.

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
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-476 · NULL Pointer Dereference

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✗ → ✓

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References

Show all references (5 more)

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

All records