CVE-2026-6681

Memory corruption via ignored PKCS#7 output size

Published Jun 25, 2026 · Updated Jun 25, 2026

Out-of-bounds write in wolfSSL 3.10.0 through 5.9.0 allows attackers to corrupt memory through crafted PKCS#7 input. The PKCS#7 decode methods ignore the caller-provided outputSz capacity and copy decoded content beyond the destination buffer. Reachability depends on an application passing attacker-influenced PKCS#7 content to an affected decoder with an undersized destination buffer; the published consequence is limited to integrity.

CVSS severity1.0
Low
EPSS probability0.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in wolfSSL 3.10.0 through 5.9.0 allows attackers to corrupt memory through crafted PKCS#7 input. The PKCS#7 decode methods ignore the caller-provided outputSz capacity and copy decoded content beyond the destination buffer. Reachability depends on an application passing attacker-influenced PKCS#7 content to an affected decoder with an undersized destination buffer; the published consequence is limited to integrity.

The record

CVE
CVE-2026-6681
Published
Jun 25, 2026
Updated
Jun 25, 2026
Vendor
wolfSSL
Product
wolfSSL
Classifications
CWE-787, CWE-120
Attack vector
adjacent
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 25, 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=3.10.0 <=5.9.0

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesauthenticated

What is affected?

wolfSSL · wolfSSLversion=3.10.0 <=5.9.0

Published CVSS scores

5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
1.0wolfSSL Inc.CVSS:4.0/AV:A/AC:L/AT:P/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/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.

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No observations available

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

Weakness, pattern, technique

CWE-787Out-of-bounds Write
CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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