Heap data disclosure via unchecked PKCS7 cursor
Published Apr 9, 2026 · Updated Apr 9, 2026
Heap out-of-bounds read in wolfSSL before 5.9.1 allows attackers to read adjacent heap data through a crafted PKCS7 message. PKCS7_VerifySignedData() checks indefinite-length end-of-content markers without first confirming that the input cursor remains within the heap buffer. Exposure requires a build with PKCS7 support enabled and an application path that passes attacker-controlled SignedData to the parser, permitting data disclosure or process interruption.
Summary
What happened
Heap out-of-bounds read in wolfSSL before 5.9.1 allows attackers to read adjacent heap data through a crafted PKCS7 message. PKCS7_VerifySignedData() checks indefinite-length end-of-content markers without first confirming that the input cursor remains within the heap buffer. Exposure requires a build with PKCS7 support enabled and an application path that passes attacker-controlled SignedData to the parser, permitting data disclosure or process interruption.
The record
- CVE
- CVE-2026-5392
- Published
- Apr 9, 2026
- Updated
- Apr 9, 2026
- Vendor
- wolfSSL
- Product
- wolfSSL
- Classifications
- CWE-125
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 9, 2026CVE publishedPublication date reported by the CVE source.
- Apr 9, 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.
- Affected versionversion=0 <5.9.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
Public exploit references
- PKCS7 indefinite-length out-of-bounds regression fixtureproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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