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Not in CISA KEV
HIGH severity

CVE-2023-0286 openssl-src

HIGH

CVE-2023-0286 is a high-severity (CVSS 7.4) CWE-843 vulnerability in openssl-src. EPSS puts its 30-day exploitation probability at 59.5% (99th percentile). A fix is available for openssl-src — see the affected versions and patch details below.

X.400 address type confusion in X.509 GeneralName

Also known asGHSA-x4qr-2fvf-3mr5PYSEC-2026-800RUSTSEC-2023-0006
Published
Feb 8, 2023
Updated
Aug 12, 2026
Affected
3 pkgs
Patched
3 / 3
Exploits
None indexed
Exploitation data as of Sep 20, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2023-0286.

EPSS Exploitation Probability

via FIRST.org ↗
59.5%probability of exploitation in next 30 days
High Risk0.00%
Lower risk than most CVEs99th percentile — riskier than 99% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

How urgent is this, really

CVE-2023-0286 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE sits: patch-first territory.

Where this sits among everything scored

Of 377,636 CVEs with a current EPSS score, this one falls in the 50–90% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.

Real-World Exposure

3 pkgs affected
🦀openssl-src🦀openssl-src🐍cryptography

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io, PyPI packages — download data is not available via public APIs for these ecosystems.

Description

There is a type confusion vulnerability relating to X.400 address processing inside an X.509 GeneralName. X.400 addresses were parsed as an ASN1_STRING but the public structure definition for GENERAL_NAME incorrectly specified the type of the x400Address field as ASN1_TYPE. This field is subsequently interpreted by the OpenSSL function GENERAL_NAME_cmp as an ASN1_TYPE rather than an ASN1_STRING.

When CRL checking is enabled (i.e. the application sets the X509_V_FLAG_CRL_CHECK flag), this vulnerability may allow an attacker to pass arbitrary pointers to a memcmp call, enabling them to read memory contents or enact a denial of service. In most cases, the attack requires the attacker to provide both the certificate chain and CRL, neither of which need to have a valid signature. If the attacker only controls one of these inputs, the other input must already contain an X.400 address as a CRL distribution point, which is uncommon. As such, this vulnerability is most likely to only affect applications which have implemented their own functionality for retrieving CRLs over a network.

Affected Packages

3 total 3 fixed
EcosystemPackageVulnerable rangeFix
🦀crates.ioopenssl-srcall versions111.25.0cargo update -p openssl-src --precise 111.25.0
🦀crates.ioopenssl-src300.0.0&&< 300.0.12300.0.12cargo update -p openssl-src --precise 300.0.12
🐍PyPIcryptography0.8.1&&< 39.0.139.0.1pip install --upgrade 'cryptography==39.0.1'

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for openssl-src, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update openssl-src to 111.25.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-0286 is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2023-0286 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2023-0286. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatImportant

For shim in Red Hat Enterprise Linux 8 & 9, is not affected as shim doesn't support any CRL processing.

ProductFixed inAdvisory
JBoss Core Services for RHEL 8jbcs-httpd24-openssl-1:1.1.1k-14.el8jbcsRHSA-2023:3354
Red Hat Enterprise Linux 6 Extended Lifecycle Supportopenssl-0:1.0.1e-61.el6_10RHSA-2023:1438
Red Hat Enterprise Linux 7openssl-1:1.0.2k-26.el7_9RHSA-2023:1335
Red Hat Enterprise Linux 7.7 Advanced Update Supportopenssl-1:1.0.2k-21.el7_7.1RHSA-2024:5136
Red Hat Enterprise Linux 8edk2-0:20220126gitbb1bba3d77-4.el8RHSA-2023:2932
Red Hat Enterprise Linux 8compat-openssl10-1:1.0.2o-4.el8_10.1RHSA-2025:7895
Red Hat Enterprise Linux 8openssl-1:1.1.1k-9.el8_7RHSA-2023:1405
Red Hat Enterprise Linux 8.1 Update Services for SAP Solutionsopenssl-1:1.1.1c-6.el8_1RHSA-2023:1437

Frequently Asked Questions

There is a type confusion vulnerability relating to X.400 address processing inside an X.509 GeneralName. X.400 addresses were parsed as an ASN1_STRING but the public structure definition for GENERAL_NAME incorrectly specified the type of the x400Address field as ASN1_TYPE. This field is subsequently interpreted by the OpenSSL function GENERAL_NAME_cmp as an ASN1_TYPE rather than an ASN1_STRING. When CRL checking is enabled (i.e. the application sets the X509_V_FLAG_CRL_CHECK flag), this vulnerability may allow an attacker to pass arbitrary pointers to a memcmp call, enabling them to read mem
O3 Security · Impact-Aware SCA

Is CVE-2023-0286 in your dependencies?

O3 Security finds CVE-2023-0286 across crates.io, PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

CVE-2023-0286: openssl-src DoS (High 7.4) | O3 Security