How severe is CVE-2026-40528?

CVE-2026-40528 has a CVSS 3.x base score of 3.8, rated low severity. It is exploitable over physical access with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2026-40528 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-40528?

CVE-2026-40528 affects Opensc Project Opensc. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-40528?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-40528 have an EU (EUVD) identifier?

Yes. CVE-2026-40528 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-33320.

When was CVE-2026-40528 published?

CVE-2026-40528 was published on 2026-05-29 and last updated on 2026-06-17.

CVE-2026-40528

CVE-2026-40528 is a low-severity vulnerability in Opensc Project Opensc with a CVSS 3.x base score of 3.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-121.

Key facts

Severity: Low (CVSS 3.x base score 3.8)
CVSS v4: 1.0
EPSS exploit prediction: 0% (4th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-33320
Weakness: CWE-121
Affected product: Opensc Project Opensc
Published: 2026-05-29
Last modified: 2026-06-17

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.

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 3.x base score of 3.8, rated low severity. It is exploitable over physical access with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2026-40528 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-40528?: CVE-2026-40528 affects Opensc Project Opensc. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-40528?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-40528 have an EU (EUVD) identifier?: Yes. CVE-2026-40528 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-33320.
When was CVE-2026-40528 published?: CVE-2026-40528 was published on 2026-05-29 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:opensc_project:opensc:*:*:*:*:*:*:*:*

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