CVE-2026-6291: Software Security Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-hvwm-w7rw-23cv
Share
CVSS 6.5
CWE-208
Published
Advisory Summary

CVE-2026-6291 is a MODERATE (CVSS 6.5) security vulnerability vulnerability (CWE-208: Observable Timing Discrepancy) affecting Software libraries in the Maven ecosystem. The weakness occurs when two separate operations in a product require different amounts of time to complete, in a way that is observable to an actor and reveals security-relevant information about the state of the product, such as whether a particular operation was successful or not.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-6291 at a Glance

CVE Identifier CVE-2026-6291
GHSA Identifier GHSA-hvwm-w7rw-23cv
Severity MODERATE
CVSS v3.1 Base Score 6.5
CWE Classification CWE-208: Observable Timing Discrepancy
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 6.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2026-6291

To remediate this vulnerability, upgrade all affected Software dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-6291, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

Analyze the terminal output to locate any version of Software in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The mvn dependency:tree command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-208: Observable Timing Discrepancy, where two separate operations in a product require different amounts of time to complete, in a way that is observable to an actor and reveals security-relevant information about the state of the product, such as whether a particular operation was successful or not. In Software, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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.

References

NVD — CVE-2026-6291 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-6291
Software Source Repository REPOSITORY
https://github.com/wolfSSL/wolfssl/pull/10203
Software Security Information SECURITY
https://www.wolfssl.com/docs/security-vulnerabilities

Frequently Asked Questions

What is CVE-2026-6291?
CVE-2026-6291 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-208: Observable Timing Discrepancy.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-6291?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-6291?
CVE-2026-6291 has a CVSS v3.1 base score of 6.5 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
What CWE is associated with CVE-2026-6291?
CVE-2026-6291 is classified under CWE-208: Observable Timing Discrepancy (Two separate operations in a product require different amounts of time to complete, in a way that is observable to an actor and reveals security-relevant information about the state of the product, such as whether a particular operation was successful or not.).
How can I check Maven dependencies for CVE-2026-6291?
Run the dependency tree command: 'mvn dependency:tree'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-hvwm-w7rw-23cv",
  "modified" : "2026-06-26T18:33:49Z",
  "published" : "2026-06-25T18:30:41Z",
  "aliases" : [ "CVE-2026-6291" ],
  "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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "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/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"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-6291"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/wolfSSL/wolfssl/pull/10203"
  }, {
    "type" : "WEB",
    "url" : "https://www.wolfssl.com/docs/security-vulnerabilities"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-208" ],
    "severity" : "MODERATE",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-06-25T18:16:41Z"
  }
}