A flaw has been found in OpenSC up to 0.27.1. The impacted element is the function setcos_construct_fci_44 of the file src/libopensc/card-setcos.c. Executing a manipulation of the argument type_attr can lead to stack-based buffer overflow. The attack can be launched remotely. This patch is called ad730304052937c32b4eb489a06835ac6123632c. It is best practice to apply a patch to resolve this issue.
CVE-2026-103531
MEDIUMPre-NVD 5.55.5—Trending — 4 sources updated this week
EchelonGraph scoreHIGH confidence
Score 5.5 from GitHub Security Advisory published 2026-10-01. A secondary CVSS source baseline 5.5; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
5.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 5.5Exploit: None knownExposed services: Not assessed
An upstream fix is merged but not yet released — mitigate (WAF / firewall / segmentation) until the release ships, then apply it.
- CVSS v3
- 5.5
- EG Score
- 5.5MEDIUMhigh confidence
- EG Risk
- 29EG Risk 29/100CISA SSVC
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 computedSeverity55% × 45%Exploitation0% × 40%Automatability30% × 15%CISA SSVC: Track at low or medium mission impact; Track or Attend at high (mission-essential systems).Action: An upstream fix is merged but not yet in a tagged release. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high until it ships, then apply the release. - EPSS PROB
- 0.2%
- EPSS %ILE
- 8th
- KEV
- Not listed
CISA SSVCTrack at low or medium mission impact; Track or Attend at high (mission-essential systems).
An upstream fix is merged but not yet in a tagged release. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high until it ships, then apply the release.
Exploitation none (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table
Published
October 1, 2026
Last Modified
October 1, 2026
Advisory Details (3)
Auto-updated Oct 1, 2026Upstream fix merged — awaiting tagged release. Sources: github_commit, github_pr.
github_pr
setcos: Fix buffer overflow in setcos_construct_fci_44
Fix merged in OpenSC/OpenSC PR #3812 on 2026-09-02 — awaiting tagged release
https://github.com/OpenSC/OpenSC/pull/3812github_commit
commit ad7303040529 (OpenSC/OpenSC)
Fix landed in OpenSC/OpenSC commit ad7303040529 — awaiting tagged release
https://github.com/OpenSC/OpenSC/commit/ad730304052937c32b4eb489a06835ac6123632cgeneric
GitHub - OpenSC/OpenSC: Open source smart card tools and middleware. PKCS#11/MiniDriver · GitHub
https://github.com/OpenSC/OpenSC/Vendor Advisories for CVE-2026-103531(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(3 across 3 ecosystems)
Debian:12(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| opensc | 0.23.0-0.3 ... 0.27.1-2 (18 versions) |
| — |
Debian:13(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| opensc | 0.26.1-2 ... 0.27.1-2 (6 versions) |
| — |
Debian:14(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| opensc | 0.26.1-2 ... 0.27.1-2 (6 versions) |
| — |
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 13× in last 7d / 13× 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.
- 2026-10-05 01:54 UTCEG score recompute
- 2026-10-05 01:54 UTCGHSA enrichment
- 2026-10-04 23:21 UTCEPSS rescore
- 2026-10-04 02:00 UTCEG score recompute
- 2026-10-04 02:00 UTCGHSA enrichment
- 2026-10-03 14:25 UTCEPSS rescore
- 2026-10-03 02:07 UTCEG score recompute
- 2026-10-03 02:07 UTCGHSA enrichment
- 2026-10-02 02:12 UTCEG score recompute
- 2026-10-02 02:11 UTCGHSA enrichment
- 2026-10-01 02:13 UTCEG score recompute
- 2026-10-01 01:17 UTCEG score recompute
- 2026-10-01 01:15 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Same CWE
10 shownCWE-121 · CWE-119
Frequently asked(5)
What is CVE-2026-103531?
CVE-2026-103531 is a medium vulnerability published on October 1, 2026. A flaw has been found in OpenSC up to 0.27.1. The impacted element is the function setcosconstructfci44 of the file src/libopensc/card-setcos.c. Executing a manipulation of the argument typeattr can lead to stack-based buffer overflow. The attack can be launched remotely. This patch is called…
When was CVE-2026-103531 disclosed?
CVE-2026-103531 was first published on October 1, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-103531 actively exploited?
CVE-2026-103531 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (8th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-103531?
CVE-2026-103531 has a CVSS base score of 5.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-103531?
An upstream fix for CVE-2026-103531 has been merged but is not yet in a tagged release. Until it ships, restrict network exposure of the affected system or apply the vendor's mitigation, then update to the release that contains the fix. The vendor advisories EchelonGraph has for CVE-2026-103531 are linked in the Vendor Advisories panel on this page.
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-103531
Is Your Infrastructure Affected by CVE-2026-103531?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.