CVE-2026-75900
Swtpm: swtpm: out-of-bounds read in swtpm_nvram_checkheader due to sizeof(pointer) vs sizeof(struct) mismatch
Description
An out-of-bounds read vulnerability was found in swtpm's SWTPM_NVRAM_CheckHeader() function. The entry guard checks the buffer length against sizeof(bh), where bh is a pointer, instead of sizeof(*bh), the actual struct size. This allows an undersized buffer to pass validation, causing a 2-byte heap overread on 64-bit systems (6 bytes on 32-bit) when accessing the totlen field. This may cause daemon termination on some platforms and leaks heap data to the log.
INFO
Published Date :
Aug. 19, 2026, 8:17 a.m.
Last Modified :
Aug. 19, 2026, 8:17 a.m.
Remotely Exploit :
No
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-75900
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | 53f830b8-0a3f-465b-8143-3b8a9948e749 | ||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Correct buffer size checks in SWTPM_NVRAM_CheckHeader().
- Validate buffer length against actual struct size.
- Ensure totlen field access is bounds-checked.
- Update swtpm to the latest version.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-75900.
| URL | Resource |
|---|---|
| https://access.redhat.com/security/cve/CVE-2026-75900 | |
| https://bugzilla.redhat.com/show_bug.cgi?id=2517910 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-75900 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-75900
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-75900 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-75900 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Aug. 19, 2026
Action Type Old Value New Value Added Affected [{'cpes': ['cpe:/o:redhat:enterprise_linux:10'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 10', 'packageName': 'swtpm', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:8'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 8', 'packageName': 'virt:rhel/swtpm', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:9'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux 9', 'packageName': 'swtpm', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}] Added Description An out-of-bounds read vulnerability was found in swtpm's SWTPM_NVRAM_CheckHeader() function. The entry guard checks the buffer length against sizeof(bh), where bh is a pointer, instead of sizeof(*bh), the actual struct size. This allows an undersized buffer to pass validation, causing a 2-byte heap overread on 64-bit systems (6 bytes on 32-bit) when accessing the totlen field. This may cause daemon termination on some platforms and leaks heap data to the log. Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H Added CWE CWE-125 Added Reference https://access.redhat.com/security/cve/CVE-2026-75900 Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2517910