CVE-2023-40550Shim: out-of-bound read in verify_buffer_sbat()
- 5.5MediumCVSS base score
- 0.39%Exploitation in 30 daysEPSS · top 66% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
An out-of-bounds read flaw was found in Shim when it tried to validate the SBAT information. This issue may expose sensitive data during the system's boot phase.
Timeline
ID reserved
By redhat
- 6 months later
· 6 months later
Published
- 24 months later
· 24 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| redhatCNA (assigner) | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N |
| NVDNVD · Modified | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N |
- EPSS (exploitation in 30 days)
- 0.39% · top 66% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.
Affected products
Red Hat · Red Hat Enterprise Linux 7
- unaffected 0:15.8-3.el7 – < *
Red Hat · Red Hat Enterprise Linux 7
- unaffected 0:15.8-1.el7 – < *
Red Hat · Red Hat Enterprise Linux 8
- unaffected 0:15.8-4.el8_9 – < *
Red Hat · Red Hat Enterprise Linux 8.2 Advanced Update Support
- unaffected 0:15.8-2.el8_2 – < *
Red Hat · Red Hat Enterprise Linux 8.2 Telecommunications Update Service
- unaffected 0:15.8-2.el8_2 – < *
Red Hat · Red Hat Enterprise Linux 8.2 Update Services for SAP Solutions
- unaffected 0:15.8-2.el8_2 – < *
Red Hat · Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
- unaffected 0:15.8-2.el8_4 – < *
Red Hat · Red Hat Enterprise Linux 8.4 Telecommunications Update Service
- unaffected 0:15.8-2.el8_4 – < *
Red Hat · Red Hat Enterprise Linux 8.4 Update Services for SAP Solutions
- unaffected 0:15.8-2.el8_4 – < *
Red Hat · Red Hat Enterprise Linux 8.6 Extended Update Support
- unaffected 0:15.8-2.el8_6 – < *
Red Hat · Red Hat Enterprise Linux 8.8 Extended Update Support
- unaffected 0:15.8-2.el8 – < *
Red Hat · Red Hat Enterprise Linux 8.8 Extended Update Support
- unaffected 0:15.8-2.el8 – < *
Red Hat · Red Hat Enterprise Linux 9
- unaffected 0:15.8-4.el9_3 – < *
Red Hat · Red Hat Enterprise Linux 9.0 Extended Update Support
- unaffected 0:15.8-3.el9 – < *
Red Hat · Red Hat Enterprise Linux 9.0 Extended Update Support
- unaffected 0:15.8-2.el9 – < *
Red Hat · Red Hat Enterprise Linux 9.0 Extended Update Support
- unaffected 0:15.8-2.el9 – < *
Red Hat · Red Hat Enterprise Linux 9.2 Extended Update Support
- unaffected 0:15.8-3.el9_2 – < *
References
References12
- RHSA-2024:1834 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
- RHSA-2024:1835 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
- RHSA-2024:1873 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
- RHSA-2024:1876 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
- RHSA-2024:1883 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
- RHSA-2024:1902 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
- RHSA-2024:1903 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
- RHSA-2024:1959 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
- RHSA-2024:2086 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
- https://access.redhat.com/security/cve/CVE-2023-40550 (opens in a new tab)vdb-entryx_refsource_REDHATx_transferred
- RHBZ#2259915 (opens in a new tab)issue-trackingx_refsource_REDHATx_transferred
- https://lists.debian.org/debian-lts-announce/2024/05/msg00009.html (opens in a new tab)x_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2023-45121 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2023-40550)Record last updated .