CVE-2026-40528

EUVD-2026-33320

29.05.2026, 14:16

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.

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
VulnCheck	CNA	3.8 LOW	PHYSICAL	HIGH	NONE	CVSS:3.1/AV:P/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:L

Base Score

CVSS 3.x

EPSS Score

Percentile: 4%

Affected Products (NVD)

Vendor	Product	Version
opensc_project	opensc	𝑥 < 0.27.0

𝑥

= Vulnerable software versions

Early Detection

Affected products identified ahead of NVD analysis through intelligence sources.

Vendor	Product	Version	Source
opensc-project	opensc	𝑥 < 0.27.0	CNA

Azure Linux Releases

Azure Package

Release

opensc

Azure Linux 3.0

0:0.27.0-1.azl3

fixed

Common Weakness Enumeration

CWE-121 - Stack-based Buffer Overflow
A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).

References

https://github.com/OpenSC/OpenSC/commit/0358817ec74aeca654f83e7709c7720b14c5db59

https://www.vulncheck.com/advisories/opensc-buffer-overrun-in-do-key-value-via-profile-c