CVE-2026-5778

Integer underflow leads to out-of-bounds access in sniffer ChaCha decrypt path.

MEDIUM
6.5
CVSS Score
Published: April 9, 2026 at 09:45 PM UTC
Updated: June 17, 2026 at 10:59 AM UTC
1 product affected across 1 vendorwolfSSL

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Severity
MEDIUM6.5
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

Integer underflow in wolfSSL packet sniffer <= 5.9.0 allows an attacker to cause a program crash in the AEAD decryption path by injecting a TLS record shorter than the explicit IV plus authentication tag into traffic inspected by ssl_DecodePacket. The underflow wraps a 16-bit length to a large value that is passed to AEAD decryption routines, causing a large out-of-bounds read and crash. An unauthenticated attacker can trigger this remotely via malformed TLS Application Data records.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v ≤ 5.9.0v < 5.9.1

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (1)

Issue TrackingPatch
Source: cverecord
https://github.com/wolfSSL/wolfssl/pull/10125

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-191

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