Heap-based buffer overflow in the KCAPI ECC code path of wc_ecc_import_x963_ex() in wolfSSL wolfcrypt allows a remote attacker to write attacker-controlled data past the bounds of the pubkey_raw buffer via a crafted oversized EC public key point. The WOLFSSL_KCAPI_ECC code path copies the input to key->pubkey_raw (132 bytes) using XMEMCPY without a bounds check, unlike the ATECC code path which includes a length validation. This can be triggered during TLS key exchange when a malicious peer sends a crafted ECPoint in ServerKeyExchange.
CVE-2026-4395
CRITICALNVD 9.89.8—Trending — 4 sources updated this week
EchelonGraph scoreMEDIUM confidence
Score 9.8 from GitHub Security Advisory (severity: LOW) published 2026-03-19. the CNA's CVSS baseline 1.3; sources differ by 8.5.
Triggered by: GitHub Security Advisory CVSS
Sources: cna:wolfssl, ghsa
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.8Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 9.8
- EG Score
- 9.8(medium)
- EG Risk
- 44(Track)EG Risk 44/100SSVC: 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 computedSeverity98% × 45%Exploitation0% × 40%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 27%
- KEV
- Not listed
Published
March 19, 2026
Last Modified
June 17, 2026
Advisory Details (1)
Auto-updated Jul 27, 2026Upstream fix merged — awaiting tagged release. Sources: github_pr.
github_pr
Check raw pubkey length in wc_ecc_import_x963 before copying to it for KCAPI case.
Fix merged in wolfSSL/wolfssl PR #9988 on 2026-03-17 — awaiting tagged release
https://github.com/wolfSSL/wolfssl/pull/9988Vendor Advisories for CVE-2026-4395(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 4× in last 7d / 4× 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.
- 2026-07-28 15:37 UTCEPSS rescore
- 2026-07-27 12:51 UTCEG score recompute
- 2026-07-27 12:51 UTCGHSA enrichment
- 2026-07-27 12:50 UTCOSV refresh
Frequently asked(5)
What is CVE-2026-4395?
CVE-2026-4395 is a critical vulnerability published on March 19, 2026. Heap-based buffer overflow in the KCAPI ECC code path of wceccimportx963ex() in wolfSSL wolfcrypt allows a remote attacker to write attacker-controlled data past the bounds of the pubkeyraw buffer via a crafted oversized EC public key point. The WOLFSSLKCAPIECC code path copies the input to…
When was CVE-2026-4395 disclosed?
CVE-2026-4395 was first published in the National Vulnerability Database on March 19, 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-2026-4395 actively exploited?
CVE-2026-4395 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 73.0% of all scored CVEs.
What is the CVSS score of CVE-2026-4395?
CVE-2026-4395 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-4395?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-4395, 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-2026-4395
Is Your Infrastructure Affected by CVE-2026-4395?
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