CVE-2023-39193

Kernel crash or disclosure via unchecked flag count

Published Oct 9, 2023 · Updated Nov 6, 2025

Out-of-bounds read in the Netfilter SCTP matcher in Red Hat Enterprise Linux 8 and 9 allows local users to disclose kernel memory. The sctp_mt_check function accepts a flag_count larger than the flag_info array, causing match_flags to read beyond that fixed-size array. Reaching the flaw requires CAP_NET_ADMIN; a crafted SCTP match rule can expose kernel memory or crash the system without modifying data.

CVSS severity6.1
Medium
EPSS probability0.41%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in the Netfilter SCTP matcher in Red Hat Enterprise Linux 8 and 9 allows local users to disclose kernel memory. The sctp_mt_check function accepts a flag_count larger than the flag_info array, causing match_flags to read beyond that fixed-size array. Reaching the flaw requires CAP_NET_ADMIN; a crafted SCTP match rule can expose kernel memory or crash the system without modifying data.

The record

CVE
CVE-2023-39193
Published
Oct 9, 2023
Updated
Nov 6, 2025
Vendor
Red Hat
Product
Red Hat Enterprise Linux 8
Classifications
CWE-125, T1499
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Oct 9, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 6, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Red Hat · Red Hat Enterprise Linux 8Affected versions are unavailable in this record.
Red Hat · Red Hat Enterprise Linux 9Affected versions are unavailable in this record.

Published CVSS scores

6.1Red HatCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:L
6.0NISTCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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