CVE-2026-6291

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Source
https://cve.org/CVERecord?id=CVE-2026-6291
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-6291.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-6291
Downstream
Published
2026-06-25T16:41:42.232Z
Modified
2026-07-16T03:48:47.564610536Z
Severity
  • 6.0 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N CVSS Calculator
Summary
Bleichenbacher padding oracle in PKCS#7 KTRI RSA PKCS#1 v1.5 decryption
Details

Bleichenbacher padding oracle in PKCS#7 KTRI decryption. When decrypting PKCS#7 EnvelopedData using RSA PKCS#1 v1.5 key transport, wolfSSL returned distinguishable error codes depending on whether RSA padding validation failed versus whether the decrypted content was malformed. An attacker able to submit crafted EnvelopedData messages and observe error responses could use this as a padding oracle to incrementally recover the encrypted Content Encryption Key (CEK). The fix generates a deterministic pseudo-random fake CEK on padding failure (via HMAC-SHA256) and proceeds with decryption identically, using constant-time operations throughout, so that all failure paths produce the same error regardless of padding validity.

Database specific 
{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6291.json",
    "cwe_ids": [
        "CWE-208"
    ],
    "cna_assigner": "wolfSSL"
}
References

Affected packages

Git / github.com/wolfssl/wolfssl

Affected ranges

Type
GIT
Repo
https://github.com/wolfssl/wolfssl
Events
Introduced
f27159f2db71c4142629c861506de332fe5911be
Fixed
ac01707f552c611fbd135cc723b2682b3e7f80f2
Database specific 
{
    "extracted_events": [
        {
            "introduced": "3.9.10"
        },
        {
            "last_affected": "5.9.1"
        },
        {
            "fixed": "5.9.2"
        }
    ],
    "source": [
        "AFFECTED_FIELD",
        "CPE_RANGE"
    ],
    "cpe": "cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:*"
}

Affected versions

Other
WCv4-rng-stable
l
list
wolfEntropy1
wolfEntropy2d
WCv5.*
WCv5.0-RC10
WCv5.0-RC11
WCv5.0-RC12
WCv5.0-RC9
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
v3.9.10b
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
v5.9.1-stable

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-6291.json"