SARA / Free Tools / CVE / CVE-2023-39189

CVE-2023-39189 — A flaw was found in the Netfilter subsystem in the Linux kernel

A flaw was found in the Netfilter subsystem in the Linux kernel. The nfnl_osf_add_callback function did not validate the user mode controlled opt_num field. This flaw allows a local privileged (CAP_NET_ADMIN) attacker to trigger an out-of-bounds read, leading to a crash or inform

CVSS
5.1 MEDIUM
EPSS
0.40% (top 67.10%)
CWE
—
Published
2023-10-09T18:15:10.160
Last modified
2026-10-15T00:16:35.363
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:L

01What is this vulnerability?

A flaw was found in the Netfilter subsystem in the Linux kernel. The nfnl_osf_add_callback function did not validate the user mode controlled opt_num field. This flaw allows a local privileged (CAP_NET_ADMIN) attacker to trigger an out-of-bounds read, leading to a crash or information disclosure.

02Affected products

No structured affected-product list available — see references below for vendor advisories.

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

09References

Want this in your SOAR or SIEM?
SARA's API returns EPSS, CVSS, KEV, and an analyst-grade summary in one call.
Read the API reference →