High severity · published May 29, 2026
CVE-2026-40528
OpenSC < 0.27.0 Buffer Overrun in do_key_value() via profile.c
7.8
CVSS
0.2%
EPSS
No
On KEV
Description
OpenSC before 0.27.0, fixed in commit 0358817, contains a stack and heap buffer overrun vulnerability in the do_key_value() function in src/pkcs15init/profile.c that allows attackers to corrupt memory by supplying a crafted profile configuration file. During pkcs15-init invocation, a key value entry beginning with '=' followed by more than sizeof(keybuf) characters is copied into keybuf via memcpy without a length check, causing both stack and heap buffer overruns.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 8% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
OP
OpenSC · OpenSC
before 0.27.0; before 0358817ec74aeca654f83e7709c7720b14c5db59 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-40528
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-40528
Patch
https://github.com/OpenSC/OpenSC/commit/0358817ec74aeca654f83e7709c7720b14c5db59
Third Party Advisory
https://www.vulncheck.com/advisories/opensc-buffer-overrun-in-do-key-value-via-profile-c
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