CVE-2026-40528

LOWCVSS 1/10EPSS 0.15%

Last modified

CVE-2026-40528 is a low-severity vulnerability rated 1/10 on the CVSS scale. 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.. EPSS estimates a 0.15% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
7.8/10

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS 4.0
1/10

CVSS:4.0/AV:P/AC:H/AT:N/PR:N/UI:P/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability
0.15%

4.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
Opensc ProjectOpensc< 0.27.0

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-40528?
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.
How severe is CVE-2026-40528?
CVE-2026-40528 has a CVSS score of 1/10 (LOW severity). The EPSS model estimates a 0.15% probability of exploitation in the next 30 days.
How do I fix CVE-2026-40528?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-40528?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST