HOMEVULNERABILITIESCVE-2026-40528
HIGH

CVE-2026-40528

CWE-121Published: May 29, 2026· Updated: Jun 3, 2026

7.8
CVSS v3.1
EPSS:0.01%probability of exploitation in 30 daysPercentile:0.3th

Official 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.

NVD Source

Technical Analysis

CVE-2026-40528 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 7.8.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorLocal
Attack ComplexityLow
Privileges Req.None
User InteractionRequired
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected Vendors & Products

opensc_project1 product
opensc
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://github.com/OpenSC/OpenSC/commit/0358817ec74aeca654f83e7709c7720b14c5db59
ADVISORYhttps://www.vulncheck.com/advisories/opensc-buffer-overrun-in-do-key-value-via-profile-c

All References (2)

→
https://github.com/OpenSC/OpenSC/commit/0358817ec74aeca654f83e7709c7720b14c5db59Patch
→
https://www.vulncheck.com/advisories/opensc-buffer-overrun-in-do-key-value-via-profile-cThird Party Advisory

Quick Facts

CVE IDCVE-2026-40528
CVSS Score7.8 / 10
SeverityHIGH
WeaknessCWE-121
CISA KEVNo
EPSS (30d)0.01%
Affected1 vendor
PublishedMay 29, 2026

Related CVEs (CWE-121)

CVE-2026-12846
10.0
CVE-2026-12485
10.0
CVE-2026-37541
10.0
CVE-2026-12848
10.0
CVE-2017-20230
10.0
CVE-2026-12847
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2026-40528 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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