Service interrupt via pointer-size header check
Published Aug 19, 2026 · Updated Aug 19, 2026
Out-of-bounds read in swtpm in Red Hat Enterprise Linux 8 and 9 allows local users to leak heap data or interrupt service via crafted state blobs. SWTPM_NVRAM_CheckHeader in src/swtpm/swtpm_nvstore.c compares the caller-supplied buffer length to sizeof(bh), a pointer, instead of the 10-byte packed blobheader, so an 8-byte control-channel blob passes validation and bh->totlen reads past the heap allocation. Exploitation requires local low-privileged access to the swtpm control channel; the out-of-bounds value is logged, and some 32-bit or non-glibc environments can terminate the daemon backing a VM TPM.
Summary
What happened
Out-of-bounds read in swtpm in Red Hat Enterprise Linux 8 and 9 allows local users to leak heap data or interrupt service via crafted state blobs. SWTPM_NVRAM_CheckHeader in src/swtpm/swtpm_nvstore.c compares the caller-supplied buffer length to sizeof(bh), a pointer, instead of the 10-byte packed blobheader, so an 8-byte control-channel blob passes validation and bh->totlen reads past the heap allocation. Exploitation requires local low-privileged access to the swtpm control channel; the out-of-bounds value is logged, and some 32-bit or non-glibc environments can terminate the daemon backing a VM TPM.
The record
- CVE
- CVE-2026-75900
- Published
- Aug 19, 2026
- Updated
- Aug 19, 2026
- Vendor
- 389 Directory Server
- Product
- Red Hat Enterprise Linux
- Classifications
- CWE-125
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 19, 2026CVE publishedPublication date reported by the CVE source.
- Aug 19, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What conditions does exploitation require?
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Weakness, pattern, technique
Public exploit references
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