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CVE-2023-53296· NVD / CVE Program· CNA Linux

sctp: check send stream number after wait_for_sndbuf

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: 0.14% (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 0443fff49d6352160c200064156c25898bd9f58c, 2584024b23552c00d95b50255e47bd18d306d31a, 667eb99cf7c15fe5b0ecefe75cf658e20ef20c9f.

Low priority for now. Upgrade to Linux Linux 0443fff49d6352160c200064156c25898bd9f58c, 2584024b23552c00d95b50255e47bd18d306d31a, 667eb99cf7c15fe5b0ecefe75cf658e20ef20c9f 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: sctp: check send stream number after wait_for_sndbuf This patch fixes a corner case where the asoc out stream count may change after wait_for_sndbuf. When the main thread in the client starts a connection, if its out stream count is set to N while the in stream count in the server is set to N - 2, another thread in the client keeps sending the msgs with stream number N - 1, and waits for sndbuf before processing INIT_ACK. However, after processing INIT_ACK, the out stream count in the client is shrunk to N - 2, the same to the in stream count in the server. The crash occurs when the thread waiting for sndbuf is awake and sends the msg in a non-existing stream(N - 1), the call trace is as below: KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f] Call Trace: <TASK> sctp_cmd_send_msg net/sctp/sm_sideeffect.c:1114 [inline] sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1777 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1199 [inline] sctp_do_sm+0x197d/0x5310 net/sctp/sm_sideeffect.c:1170 sctp_primitive_SEND+0x9f/0xc0 net/sctp/primitive.c:163 sctp_sendmsg_to_asoc+0x10eb/0x1a30 net/sctp/socket.c:1868 sctp_sendmsg+0x8d4/0x1d90 net/sctp/socket.c:2026 inet_sendmsg+0x9d/0xe0 net/ipv4/af_inet.c:825 sock_sendmsg_nosec net/socket.c:722 [inline] sock_sendmsg+0xde/0x190 net/socket.c:745 The fix is to add an unlikely check for the send stream number after the thread wakes up from the wait_for_sndbuf.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Sep 16, 2025
Updated
Jun 17, 2026
EPSS
0.1% · 3th 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 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

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-2023-53296

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 kernel4.15 and later · before 4.19.281
  • linux linux kernel4.20 and later · before 5.4.241
  • linux linux kernel5.5 and later · before 5.10.178
  • linux linux kernel5.11 and later · before 5.15.107
  • linux linux kernel5.16 and later · before 6.1.24
  • linux linux kernel6.2 and later · before 6.2.11
  • linux linux kernel6.3

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

    • 4.15affected
    • 5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 and later · before 9346a1a21142357972a6f466ba6275ddc54b04acaffected · git
    • 5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 and later · before 0443fff49d6352160c200064156c25898bd9f58caffected · git
    • 5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 and later · before b4b6dfad41aaae9e36e44327b18d5cf4b20dd2ceaffected · git
    • 5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 and later · before 667eb99cf7c15fe5b0ecefe75cf658e20ef20c9faffected · git
    • 5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 and later · before d2128636b303aa9cf065055402ee6697409a8837affected · git
    • 5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 and later · before a615e7270318fa0b98bf1ff38daf6cf52d840312affected · git
    • 5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 and later · before 2584024b23552c00d95b50255e47bd18d306d31aaffected · git
    • before 4.15not affected · semver
    • 4.19.281 and later · up to and including 4.19.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.25-16.1.25-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • 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
  • CVE-2016-5195Race condition in mm/gup.c in the Linux kernel 2.x through 4.x before 4.8.3 allows local users to gain privileges by leveraging incorrect haKEV
    83Now

Published before and after this one in the same product

  • ← EarlierCVE-2023-53294Sep 16, 2025 · fs/ntfs3: Fix null-ptr-deref on inode->i_op in ntfs_lookup()
    22Monitor
  • ← EarlierCVE-2023-53295Sep 16, 2025 · udf: Do not update file length for failed writes to inline files
    22Monitor
  • Later →CVE-2023-53297Sep 16, 2025 · Bluetooth: L2CAP: fix "bad unlock balance" in l2cap_disconnect_rsp
    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 Linux0443fff49d6352160c200064156c25898bd9f58cVendor (CNA)
Linux Linux2584024b23552c00d95b50255e47bd18d306d31aVendor (CNA)
Linux Linux667eb99cf7c15fe5b0ecefe75cf658e20ef20c9fVendor (CNA)
Linux Linux9346a1a21142357972a6f466ba6275ddc54b04acVendor (CNA)
Linux Linuxa615e7270318fa0b98bf1ff38daf6cf52d840312Vendor (CNA)
Linux Linuxb4b6dfad41aaae9e36e44327b18d5cf4b20dd2ceVendor (CNA)
Linux Linuxd2128636b303aa9cf065055402ee6697409a8837Vendor (CNA)
debian:linux6.1.25-1 · 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.

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

  • 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✗ → ✓

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

References

Show all references (6 more)

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

All records