CVE-2025-66038

3.9 LOW 0.3% exploit odds Fix listed Memory safety

What it is

OpenSC is an open source smart card tools and middleware. Prior to version 0.27.0, sc_compacttlv_find_tag searches a compact-TLV buffer for a given tag. In compact-TLV, a single byte encodes the tag (high nibble) and value length (low nibble). With a 1-byte buffer {0x0A}, the encoded element claims tag=0 and length=10 but no value bytes follow. Calling sc_compacttlv_find_tag with search tag 0x00 returns a pointer equal to buf+1 and outlen=10 without verifying that the claimed value length fits within the remaining buffer. In cases where the sc_compacttlv_find_tag is provided untrusted data (such as being read from cards/files), attackers may be able to influence it to return out-of-bounds pointers leading to downstream memory corruption when subsequent code tries to dereference the pointer. This issue has been patched in version 0.27.0.

At a glance

Exploitability: Can be exploited with physical access without logging in. Limited direct impact.
Exploit odds: 0.3% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-03-30 18:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-06-17 09:56 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.3% in the next 30 days (EPSS).
Severity: 3.9 LOW (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-03-30 18:16 UTC
Last modified: 2026-06-17 09:56 UTC
Exploit probability: 0.3% · EPSS, next 30 days
Weakness: CWE-126
Record status: Analyzed

Affected

Opensc Project Opensc < 0.27.0

Attack profile CVSS 3.1 · 3.9

Attack vector: Physical
Complexity: High
Privileges needed: None
User interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: Low
Availability: Low

Raw vector

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

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2025-66038.md and follow it. Check whether this project is affected by CVE-2025-66038. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record