CVE-2026-5477

See a problem?
Please try reporting it to the source first.
Source
https://cve.org/CVERecord?id=CVE-2026-5477
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-5477.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-5477
Downstream
Published
2026-04-10T05:06:22.884Z
Modified
2026-07-16T03:48:42.207127299Z
Severity
  • 8.2 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N CVSS Calculator
Summary
Prefix-substitution forgery via integer overflow in wolfCrypt CMAC
Details

An integer overflow existed in the wolfCrypt CMAC implementation, that could be exploited to forge CMAC tags. The function wcCmacUpdate used the guard if (cmac->totalSz != 0) to skip XOR-chaining on the first block (where digest is all-zeros and the XOR is a no-op). However, totalSz is word32 and wraps to zero after 2^28 block flushes (4 GiB), causing the guard to erroneously discard the live CBC-MAC chain state. Any two messages sharing a common suffix beyond the 4 GiB mark then produce identical CMAC tags, enabling a zero-work prefix-substitution forgery. The fix removes the guard, making the XOR unconditional; the no-op property on the first block is preserved because digest is zero-initialized by wcInitCmac_ex.

Database specific 
{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/5xxx/CVE-2026-5477.json",
    "cna_assigner": "wolfSSL",
    "cwe_ids": [
        "CWE-190"
    ]
}
References

Affected packages

Git / github.com/wolfssl/wolfssl

Affected ranges

Type
GIT
Repo
https://github.com/wolfssl/wolfssl
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Last affected
922d04b3568c6428a9fb905ddee3ef5a68db3108
Database specific 
{
    "cpe": "cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:*",
    "source": [
        "AFFECTED_FIELD",
        "CPE_RANGE"
    ],
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "last_affected": "5.9.0"
        }
    ]
}

Affected versions

Other
WCv4-rng-stable
l
list
wolfEntropy1
wolfEntropy2d
WCv5.*
WCv5.0-RC10
WCv5.0-RC11
WCv5.0-RC12
WCv5.0-RC9
v0.*
v0.5
v1.*
v1.8.8.0
v1.9.0
v2.*
v2.0.2
v2.0.3
v2.0.6
v2.0.8
v2.0rc1
v2.0rc2
v2.0rc2b
v2.0rc3
v2.4.2
v2.4.6
v2.4.7
v2.6.0
v2.6.2
v2.7.0
v2.7.2
v2.8.0
v2.8.2
v2.8.3
v2.8.4
v2.8.5
v2.8.5a
v2.8.6
v2.9.0
v2.9.1
v2.9.2
v2.9.4
v3.*
v3.10.0-stable
v3.10.0a
v3.10.2-stable
v3.10.3
v3.11.0-stable
v3.11.1-tls13-beta
v3.12.0-stable
v3.12.2-stable
v3.13.0-stable
v3.13.2
v3.13.3
v3.14.0-stable
v3.14.0a
v3.14.0b
v3.14.2
v3.14.4
v3.15.0-stable
v3.15.3-stable
v3.15.5-stable
v3.15.5a
v3.15.6
v3.15.7-stable
v3.2.0
v3.2.4
v3.2.6
v3.3.0
v3.3.3
v3.4.0
v3.4.2
v3.4.6
v3.6.8
v3.6.9
v3.7.0
v3.7.1
v3.7.3
v3.8.0
v3.9.0
v3.9.1
v3.9.10-stable
v3.9.10b
v3.9.6
v3.9.6w
v3.9.8
v4.*
v4.0.0-stable
v4.1.0-stable
v4.2.0-stable
v4.2.0c
v4.3.0-stable
v4.4.0-stable
v4.5.0-stable
v4.6.0-stable
v4.7.0-stable
v4.7.1r
v4.8.0-stable
v5.*
v5.0.0-stable
v5.1.0-stable
v5.2.0-stable
v5.2.1
v5.3.0-stable
v5.4.0-stable
v5.5.0-stable
v5.5.1-stable
v5.5.2-stable
v5.5.3-stable
v5.5.4-stable
v5.6.0-stable
v5.6.2-stable
v5.6.3-stable
v5.6.4-stable
v5.6.6-stable
v5.7.0-stable
v5.7.2-stable
v5.7.4-stable
v5.7.6-stable
v5.8.0-stable
v5.8.2-stable
v5.8.4-stable
v5.9.0-stable

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-5477.json"