CVE-2026-5479

Plaintext forgery via omitted AEAD tag comparison

Published Apr 10, 2026 · Updated Apr 10, 2026

Improper integrity validation in wolfSSL before 5.9.1 allows attackers to forge plaintext through ChaCha20-Poly1305 EVP decryption. wolfSSL_EVP_CipherFinal and related EVP finalizers return decrypted data without comparing the computed or supplied tag with the expected tag. Exposure requires an application to use this EVP decryption path and trust its output; the bounded consequence is undetected data tampering, not service interruption.

CVSS severity7.6
High
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper integrity validation in wolfSSL before 5.9.1 allows attackers to forge plaintext through ChaCha20-Poly1305 EVP decryption. wolfSSL_EVP_CipherFinal and related EVP finalizers return decrypted data without comparing the computed or supplied tag with the expected tag. Exposure requires an application to use this EVP decryption path and trust its output; the bounded consequence is undetected data tampering, not service interruption.

The record

CVE
CVE-2026-5479
Published
Apr 10, 2026
Updated
Apr 10, 2026
Vendor
wolfSSL
Product
wolfSSL
Classifications
CWE-354, T1565.002
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 10, 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 <5.9.1

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

wolfSSL · wolfSSLversion=0 <5.9.1

Published CVSS scores

7.6wolfSSL Inc.CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
8.1NIST NVDCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-354Improper Validation of Integrity Check Value
T1565.002Transmitted Data Manipulation

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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