OpenSC is an open source smart card tools and middleware. Prior to version 0.27.0, feeding a crafted input to the fuzz_pkcs15_reader harness causes OpenSC to perform an out-of-bounds heap read in the X.509/SPKI handling path. Specifically, sc_pkcs15_pubkey_from_spki_fields() allocates a zero-length buffer and then reads one byte past the end of that allocation. This issue has been patched in version 0.27.0.
CVE-2025-66037
LOWNVD 6.83.9Trending — 3 sources updated this weekElevated
EchelonGraph scoreLOW confidence
This low-severity CVE scores 3.9 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: cna:github_m
3.9EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.8Exploit: Elevated riskExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 6.8
- EG Score
- 3.9(low)
- EG Risk
- 18(Track)EG Risk 18/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity39% × 45%Exploitation0% × 40%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 17%
- KEV
- Not listed
Published
March 30, 2026
Last Modified
June 17, 2026
References (2)
- security-advisories@githubhttps://github.com/OpenSC/OpenSC/security/advisories/GHSA-m58q-rmjm-mmfx
- security-advisories@githubhttps://github.com/OpenSC/OpenSC/wiki/CVE-2025-66037
Vendor Advisories for CVE-2025-66037(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 7× in last 7d / 7× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-08-01 04:15 UTCEPSS rescore
- 2026-07-30 16:27 UTCEPSS rescore
- 2026-07-30 01:30 UTCEPSS rescore
- 2026-07-28 15:35 UTCEPSS rescore
- 2026-07-27 14:12 UTCEPSS rescore
- 2026-07-27 12:52 UTCEG score recompute
- 2026-07-27 12:52 UTCVendor advisory
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Frequently asked(5)
What is CVE-2025-66037?
CVE-2025-66037 is a low vulnerability published on March 30, 2026. OpenSC is an open source smart card tools and middleware. Prior to version 0.27.0, feeding a crafted input to the fuzzpkcs15reader harness causes OpenSC to perform an out-of-bounds heap read in the X.509/SPKI handling path. Specifically, scpkcs15pubkeyfromspki_fields() allocates a zero-length…
When was CVE-2025-66037 disclosed?
CVE-2025-66037 was first published in the National Vulnerability Database on March 30, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2025-66037 actively exploited?
CVE-2025-66037 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 83.2% of all scored CVEs.
What is the CVSS score of CVE-2025-66037?
CVE-2025-66037 has a CVSS v3 base score of 6.8 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 3.9. The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2025-66037?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-66037, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2025-66037
Is Your Infrastructure Affected by CVE-2025-66037?
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