CVE-2026-5479

HIGHCVSS 7.6/10EPSS 0.15%

Last modified

CVE-2026-5479 is a high-severity vulnerability rated 7.6/10 on the CVSS scale. In wolfSSL's EVP layer, the ChaCha20-Poly1305 AEAD decryption path in wolfSSL_EVP_CipherFinal (and related EVP cipher finalization functions) fails to verify the authentication tag before returning plaintext to the caller. When an application uses the EVP API to perform ChaCha20-Poly1305 decryption, the implementation computes or accepts the tag but does not compare it against the expected value.. EPSS estimates a 0.15% chance of exploitation in the next 30 days.

Description

In wolfSSL's EVP layer, the ChaCha20-Poly1305 AEAD decryption path in wolfSSL_EVP_CipherFinal (and related EVP cipher finalization functions) fails to verify the authentication tag before returning plaintext to the caller. When an application uses the EVP API to perform ChaCha20-Poly1305 decryption, the implementation computes or accepts the tag but does not compare it against the expected value.

Metrics

CVSS 3.1
8.1/10

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CVSS 4.0
7.6/10

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability
0.15%

4.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
WolfsslWolfssl< 5.9.1

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-5479?
In wolfSSL's EVP layer, the ChaCha20-Poly1305 AEAD decryption path in wolfSSL_EVP_CipherFinal (and related EVP cipher finalization functions) fails to verify the authentication tag before returning plaintext to the caller. When an application uses the EVP API to perform ChaCha20-Poly1305 decryption, the implementation computes or accepts the tag but does not compare it against the expected value.
How severe is CVE-2026-5479?
CVE-2026-5479 has a CVSS score of 7.6/10 (HIGH severity). The EPSS model estimates a 0.15% probability of exploitation in the next 30 days.
How do I fix CVE-2026-5479?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-5479?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST