CVE-2023-39194 — Kernel: xfrm: out-of-bounds read in __xfrm_state_filter_match()
A flaw was found in the XFRM subsystem in the Linux kernel. The specific flaw exists within the processing of state filters, which can result in a read past the end of an allocated buffer. This flaw allows a local privileged (CAP_NET_ADMIN) attacker to trigger an out-of-bounds read, potentially leading to an information disclosure.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.4% (30-day exploitation probability)+5
- Technical severity (medium)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — bugzilla.redhat.com (NIST National Vulnerability Database)
- Documented patch — www.zerodayinitiative.com (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Fedoraproject Fedora, Linux Linux Kernel, Red Hat Enterprise Linux…).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Fedoraproject | Fedora | version 38 | Vulnerable | NIST National Vulnerability Database |
| Linux | Linux Kernel | < 6.5version 6.5-rc1version 6.5-rc2version 6.5-rc3version 6.5-rc4version 6.5-rc5version 6.5-rc6 | Vulnerable | NIST National Vulnerability Database |
| Red Hat | Enterprise Linux | version 8.0version 9.0 | Vulnerable | NIST National Vulnerability Database |
| Red Hat | Red Hat Enterprise Linux 8 | versions not specified by the source | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Red Hat | Red Hat Enterprise Linux 9 | versions not specified by the source | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 4.4 | CVSS 3.1 | Medium | 0.8 | 3.6 | nvd@nist.gov via NIST National Vulnerability Database |
| 3.2 | CVSS 3.1 | Low | 1.5 | 1.4 | secalert@redhat.com via NIST National Vulnerability Database |
| 3.2 | CVSS 3.1 | Low | — | — | GitHub, Inc. via GitHub Security Advisories |
| 3.2 | CVSS 3.1 | Low | — | — | redhat via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 14, 2026 → Oct 15, 2026 · 2 reading(s) · max 0.42%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · red hat/red hat enterprise linux 8, red hat/red hat enterprise linux 9
- Record published
- Fix documented
- Affected products added · linux/linux kernel, redhat/enterprise linux, fedoraproject/fedora
- CVSS changed · 4.4
- Source status changed · → Modified
- Record created in this database
- 2023
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 14, 2026 – Oct 14, 2026
- 1× Official description updated · Oct 14, 2026 – Oct 14, 2026
References
12 on the record
- bugzilla.redhat.com/show_bug.cgi
- www.zerodayinitiative.com/advisories/ZDI-CAN-18111/
- nvd.nist.gov/vuln/detail/CVE-2023-39194
- cert-portal.siemens.com/productcert/html/ssa-398330.html
- access.redhat.com/errata/RHSA-2024:3138
- lists.debian.org/debian-lts-announce/2024/01/msg00004.html
- www.zerodayinitiative.com/advisories/ZDI-CAN-18111
- access.redhat.com/errata/RHSA-2024:2394
- cert-portal.siemens.com/productcert/html/ssa-794697.html
- access.redhat.com/security/cve/CVE-2023-39194
- github.com/advisories/GHSA-3qhf-qr39-9c9w
- access.redhat.com/errata/RHSA-2024:2950
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-104715 Cifs-utils: mount.cifs credential-file option injection allows local privilege boundary bypass 2h
- Medium CVE-2026-110924 Openssh: openssh: gssapi delegated credentials can be stored after a failed authentication 19h
- Medium CVE-2026-110927 Openssh: openssh: a compressed payload can expand past the maximum packet size 19h
- Medium CVE-2026-110923 Openssh: openssh: sftp can write outside the destination directory from a server-supplied path 1d
- Medium CVE-2026-110925 Openssh: openssh: '$' and '\' in a command-line username expand through %u 1d
- Medium CVE-2026-110926 Openssh: openssh: shared lz77 compression dictionary leaks plaintext across channels 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CISA SSVC assessment.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2023-39194 is "Kernel: xfrm: out-of-bounds read in __xfrm_state_filter_match()", rated Medium. It affects Fedora (Fedoraproject); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 4.4 describes technical severity. EPSS 0.42% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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