PatchTheCVECVE-2023-40549: An out-of-bounds read flaw was found in Shim due to the lack of proper boundary verification during the load o
CVE-2023-40549 is a medium-severity flaw (CVSS 6.2) affecting shim, fedora, enterprise linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
An out-of-bounds read flaw was found in Shim due to the lack of proper boundary verification during the load of a PE binary. This flaw allows an attacker to load a crafted PE binary, triggering the issue and crashing Shim, resulting in a denial of service.
Why this priority
- On your watchlist
A fixed release or distro patch exists.
Risk facts
| CVSS score | 6.2 (Medium) |
| Attack vector | Local |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.4% (top 65%) |
| CISA exploited list | No |
| Weakness | CWE-125 |
| Published | 2024-01-29 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2023-40549?
shim: upgrade to 15.8; fedora: mitigate or apply the listed mitigation; enterprise linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.
Is CVE-2023-40549 being exploited?
CVE-2023-40549 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2023-40549 affect?
CVE-2023-40549 affects shim, fedora, enterprise linux. Severity is medium (CVSS 6.2). An out-of-bounds read flaw was found in Shim due to the lack of proper boundary verification during the load of a PE binary. This flaw allows an attacker to load a crafted PE binary, triggering the issue and crashing Shim, resulting in a de
How urgent is CVE-2023-40549?
Priority 36/100. On your watchlist
Related CVEs
- CVE-2023-40548 HIGH 7.4 UPGRADE MITIGATE A buffer overflow was found in Shim in the 32-bit system
- CVE-2023-40547 HIGH 8.3 UPGRADE MITIGATE A remote code execution vulnerability was found in Shim
- CVE-2023-40551 MEDIUM 5.1 UPGRADE MITIGATE A flaw was found in the MZ binary format in Shim
- CVE-2023-40550 MEDIUM 5.5 UPGRADE MITIGATE An out-of-bounds read flaw was found in Shim when it tried to validate the SBAT information
- CVE-2023-40546 MEDIUM 6.2 UPGRADE MITIGATE A flaw was found in Shim when an error happened while creating a new ESL variable