CVE-2023-40551

MEDIUMNVD 5.15.1—

5.1

A flaw was found in the MZ binary format in Shim. An out-of-bounds read may occur, leading to a crash or possible exposure of sensitive data during the system's boot phase.

CVSS v3: 5.1
EG Score: 5.1(medium)
EPSS: 3.3%
KEV: Not listed

Published

January 29, 2024

Last Modified

November 21, 2024

References (23)

secalert@redhathttps://access.redhat.com/errata/RHSA-2024:1834
secalert@redhathttps://access.redhat.com/errata/RHSA-2024:1835
secalert@redhathttps://access.redhat.com/errata/RHSA-2024:1873
secalert@redhathttps://access.redhat.com/errata/RHSA-2024:1876
secalert@redhathttps://access.redhat.com/errata/RHSA-2024:1883
secalert@redhathttps://access.redhat.com/errata/RHSA-2024:1902
secalert@redhathttps://access.redhat.com/errata/RHSA-2024:1903
secalert@redhathttps://access.redhat.com/errata/RHSA-2024:1959
secalert@redhathttps://access.redhat.com/errata/RHSA-2024:2086
secalert@redhathttps://access.redhat.com/security/cve/CVE-2023-40551
secalert@redhathttps://bugzilla.redhat.com/show_bug.cgi?id=2259918
af854a3a-2127-422b-91ae-364da2661108https://access.redhat.com/errata/RHSA-2024:1834
af854a3a-2127-422b-91ae-364da2661108https://access.redhat.com/errata/RHSA-2024:1835
af854a3a-2127-422b-91ae-364da2661108https://access.redhat.com/errata/RHSA-2024:1873
af854a3a-2127-422b-91ae-364da2661108https://access.redhat.com/errata/RHSA-2024:1876

Patch Availability(9)

Vendor / Ecosystem	Fixed in / Patch	Released	Source
redhat	shim-0:15.8-2.el8_6	2024-04-29	redhat
redhat	shim-signed-0:15.8-1.el7	2024-04-23	redhat
redhat	shim-0:15.8-4.el9_3	2024-04-18	redhat
redhat	shim-0:15.8-2.el8_4	2024-04-18	redhat
redhat	shim-0:15.8-4.el8_9	2024-04-18	redhat
redhat	shim-unsigned-x64-0:15.8-2.el8	2024-04-18	redhat
redhat	shim-0:15.8-3.el9_2	2024-04-18	redhat
redhat	shim-0:15.8-2.el8_2	2024-04-16	redhat
redhat	shim-unsigned-x64-0:15.8-2.el9	2024-04-16	redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-125Out-of-bounds Read

All Vendor Advisories

(10)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 14× in last 7d / 45× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

2026-06-13 22:59 UTCEPSS rescore
2026-06-13 22:59 UTCEPSS rescore
2026-06-12 23:10 UTCEPSS rescore
2026-06-12 23:10 UTCEPSS rescore
2026-06-11 13:59 UTCEPSS rescore
2026-06-11 13:59 UTCEPSS rescore
2026-06-10 22:17 UTCEPSS rescore
2026-06-10 13:21 UTCEPSS rescore
2026-06-10 13:21 UTCEPSS rescore
2026-06-09 09:30 UTCOSV refresh
2026-06-08 14:16 UTCEPSS rescore
2026-06-08 14:16 UTCEPSS rescore
2026-06-07 15:23 UTCEPSS rescore
2026-06-07 15:23 UTCEPSS rescore
2026-06-06 13:46 UTCEPSS rescore
2026-06-06 13:46 UTCEPSS rescore
2026-06-05 22:46 UTCEPSS rescore
2026-06-05 22:46 UTCEPSS rescore
2026-06-05 06:09 UTCEPSS rescore
2026-06-05 06:09 UTCEPSS rescore
2026-06-05 06:09 UTCEPSS rescore
2026-06-04 13:11 UTCEPSS rescore
2026-06-04 13:11 UTCEPSS rescore
2026-06-02 20:12 UTCEPSS rescore
2026-06-02 20:12 UTCEPSS rescore

Show 20 more

2026-06-01 13:51 UTCEPSS rescore
2026-06-01 13:51 UTCEPSS rescore
2026-05-31 22:30 UTCEPSS rescore
2026-05-31 22:29 UTCEPSS rescore
2026-05-31 00:15 UTCEPSS rescore
2026-05-31 00:15 UTCEPSS rescore
2026-05-29 13:43 UTCEPSS rescore
2026-05-29 13:43 UTCEPSS rescore
2026-05-28 13:44 UTCEPSS rescore
2026-05-28 13:43 UTCEPSS rescore
2026-05-27 13:39 UTCEPSS rescore
2026-05-27 13:39 UTCEPSS rescore
2026-05-26 13:43 UTCEPSS rescore
2026-05-26 13:43 UTCEPSS rescore
2026-05-26 07:18 UTCEPSS rescore
2026-05-26 07:18 UTCEPSS rescore
2026-05-26 07:18 UTCEPSS rescore
2026-05-24 09:30 UTCEG score recompute
2026-05-24 09:30 UTCVendor advisory
2026-05-24 09:30 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2023-40551?

CVE-2023-40551 is a medium vulnerability published on January 29, 2024. A flaw was found in the MZ binary format in Shim. An out-of-bounds read may occur, leading to a crash or possible exposure of sensitive data during the system's boot phase.

When was CVE-2023-40551 disclosed?

CVE-2023-40551 was first published in the National Vulnerability Database on January 29, 2024, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2023-40551 actively exploited?

CVE-2023-40551 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 3.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2023-40551?

CVE-2023-40551 has a CVSS v3 base score of 5.1 (NVD).

How do I remediate CVE-2023-40551?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2023-40551, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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CVE-2023-40551

Published

Last Modified

References (23)

Patch Availability(9)

Weakness Classification(1)

All Vendor Advisories

Data Freshness Timeline

Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2023-40551?

CVE-2023-40551

Published

Last Modified

References (23)

Patch Availability(9)

Weakness Classification(1)

All Vendor Advisories

Data Freshness Timeline

Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2023-40551?

Same vendor

Same CWE

CVE-2023-40551

📅 Published

🔄 Last Modified

🔗 References (23)

Patch Availability(9)

Weakness Classification(1)

All Vendor Advisories

Data Freshness Timeline

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2023-40551?

CVE-2023-40551

📅 Published

🔄 Last Modified

🔗 References (23)

Patch Availability(9)

Weakness Classification(1)

All Vendor Advisories

Data Freshness Timeline

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2023-40551?

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