CVE-2026-3580

Secret-key disclosure via compiler-induced conditional branches

Published Mar 19, 2026 · Updated Mar 19, 2026

Timing side channel in wolfSSL 5.8.4 and earlier allows local users to recover ECC secret keys through execution-time analysis. GCC -O3 turns constant-time masking in sp_256_get_entry_256_9 into secret-dependent bnez branches rather than branchless selection. Exposure requires an RV32I build and local timing access to affected ECC scalar-multiplication operations; integrity and availability are unaffected.

CVSS severity4.7
Medium
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Timing side channel in wolfSSL 5.8.4 and earlier allows local users to recover ECC secret keys through execution-time analysis. GCC -O3 turns constant-time masking in sp_256_get_entry_256_9 into secret-dependent bnez branches rather than branchless selection. Exposure requires an RV32I build and local timing access to affected ECC scalar-multiplication operations; integrity and availability are unaffected.

The record

CVE
CVE-2026-3580
Published
Mar 19, 2026
Updated
Mar 19, 2026
Vendor
wolfSSL
Product
wolfSSL
Classifications
CWE-203, CAPEC-189
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <5.9.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

wolfSSL · wolfSSLversion=0 <5.9.0

Published CVSS scores

4.7NIST NVDCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
2.1wolfSSL Inc.CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-203Observable Discrepancy
CAPEC-189Black Box Reverse Engineering

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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