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CVE-2026-6679

DTLS 1.3 ACK serialization heap buffer overflow via integer truncation

Published: Jun 25, 2026Updated: Jun 27, 2026 Sources: CVE List NVDCWE-190
7.5HIGH
NVD MITRE
EPSS Score
0.6%
Top 55.7%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available
Self-Check
Not available

Description

A heap buffer overflow could occur in the DTLS 1.3 ACK serialization path before the connecting peer is authenticated. The buffer overflow was due to an integer truncation when computing the length of the ACK record-number list, causing an undersized buffer to be allocated and then overrun. This affects builds using DTLS 1.3 and wolfSSL version 5.9.0 and earlier. A fix was added to the 5.9.1 release.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:NI:NA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:HAvailability
High
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Weaknesses

CWE-190CWE-197CWE-787

Affected Products

wolfSSL
oss-projectaka wolfmqtt, wolfssh
wolfSSLLibraryLibrary
OSS Libraries / generic-library
and 1 more affected products View all →

Exploitability

Official Patch Available
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

2 techniques
Initial Access
Privilege Escalation
View detailed technique mapping

References

https://github.com/wolfSSL/wolfssl/pull/10116
github.com
https://www.wolfssl.com/docs/security-vulnerabilities/
wolfssl.com
News mentions
1

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