CVE-2026-86219: Software Security Vulnerability Vulnerability

CRITICAL
Advisory Identifier: GHSA-w4h4-7ff5-56xr
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CVSS 9.8
CWE-294
Published
Advisory Summary

CVE-2026-86219 is a CRITICAL (CVSS 9.8) security vulnerability vulnerability (CWE-294: Authentication Bypass by Capture-replay) affecting Software libraries in the Maven ecosystem. The weakness occurs when a capture-replay flaw exists when the design of the product makes it possible for a malicious user to sniff network traffic and bypass authentication by replaying it to the server in question to the same effect as the original message (or with minor changes).. Remediation is available in the latest vendor maintenance releases.

CVE-2026-86219 at a Glance

CVE Identifier CVE-2026-86219
GHSA Identifier GHSA-w4h4-7ff5-56xr
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-294: Authentication Bypass by Capture-replay
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 9.8

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

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

How to Fix CVE-2026-86219

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-2026-86219, 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-294: Authentication Bypass by Capture-replay, where a capture-replay flaw exists when the design of the product makes it possible for a malicious user to sniff network traffic and bypass authentication by replaying it to the server in question to the same effect as the original message (or with minor changes). 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

Authen::SASL::Perl::DIGEST_MD5 versions before 2.2100 for Perl accept replayed authentication responses via unverified nonce in server_step. server_start generates a fresh nonce and sends it in the challenge, and nothing later compares that value against the nonce the client returns. server_step derives the expected digest from the client's own parameters, so a response verifies whenever its digest matches the nonce it carries. The count table it also checks is keyed on the client-supplied nonce and starts empty in each new server object, so a captured first response, carrying `nc=00000001`, passes that too. RFC 2831 defines the nonce in the response as the value the server sent in the preceding challenge. An attacker who observes one successful `qop=auth` exchange can replay the captured response against a later session for the same service, host, realm and user, and authenticate as that user without knowing the password.

References

NVD — CVE-2026-86219 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-86219
Security Fix Commit FIX COMMIT
https://github.com/perl-authen-sasl/perl-authen-sasl/commit/94337367030612842924f697cead29964a96448d.patch
datatracker.ietf.org/doc/html/rfc2831 WEB
https://datatracker.ietf.org/doc/html/rfc2831#section-2.1.2
metacpan.org/release/ehuels/auth... WEB
https://metacpan.org/release/EHUELS/Authen-SASL-2.2000/source/lib/Authen/SASL/Perl/DIGEST_MD5.pm#L203-222
metacpan.org/release/ehuels/auth... WEB
https://metacpan.org/release/EHUELS/Authen-SASL-2.2000/source/lib/Authen/SASL/Perl/DIGEST_MD5.pm#L410-414
metacpan.org/release/ehuels/auth... WEB
https://metacpan.org/release/EHUELS/Authen-SASL-2.2100/changes
CVE Official Record — CVE-2026-86219 CVE
https://www.cve.org/CVERecord?id=CVE-2025-40918

Frequently Asked Questions

What is CVE-2026-86219?
CVE-2026-86219 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-294: Authentication Bypass by Capture-replay.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-86219?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-86219?
CVE-2026-86219 has a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-86219?
CVE-2026-86219 is classified under CWE-294: Authentication Bypass by Capture-replay (A capture-replay flaw exists when the design of the product makes it possible for a malicious user to sniff network traffic and bypass authentication by replaying it to the server in question to the same effect as the original message (or with minor changes).).
How can I check Maven dependencies for CVE-2026-86219?
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-w4h4-7ff5-56xr",
  "modified" : "2026-09-08T21:33:03Z",
  "published" : "2026-09-06T18:34:39Z",
  "aliases" : [ "CVE-2026-86219" ],
  "details" : "Authen::SASL::Perl::DIGEST_MD5 versions before 2.2100 for Perl accept replayed authentication responses via unverified nonce in server_step.\n\nserver_start generates a fresh nonce and sends it in the challenge, and nothing later compares that value against the nonce the client returns. server_step derives the expected digest from the client's own parameters, so a response verifies whenever its digest matches the nonce it carries. The count table it also checks is keyed on the client-supplied nonce and starts empty in each new server object, so a captured first response, carrying `nc=00000001`, passes that too. RFC 2831 defines the nonce in the response as the value the server sent in the preceding challenge.\n\nAn attacker who observes one successful `qop=auth` exchange can replay the captured response against a later session for the same service, host, realm and user, and authenticate as that user without knowing the password.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-86219"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/perl-authen-sasl/perl-authen-sasl/commit/94337367030612842924f697cead29964a96448d.patch"
  }, {
    "type" : "WEB",
    "url" : "https://datatracker.ietf.org/doc/html/rfc2831#section-2.1.2"
  }, {
    "type" : "WEB",
    "url" : "https://metacpan.org/release/EHUELS/Authen-SASL-2.2000/source/lib/Authen/SASL/Perl/DIGEST_MD5.pm#L203-222"
  }, {
    "type" : "WEB",
    "url" : "https://metacpan.org/release/EHUELS/Authen-SASL-2.2000/source/lib/Authen/SASL/Perl/DIGEST_MD5.pm#L410-414"
  }, {
    "type" : "WEB",
    "url" : "https://metacpan.org/release/EHUELS/Authen-SASL-2.2100/changes"
  }, {
    "type" : "WEB",
    "url" : "https://www.cve.org/CVERecord?id=CVE-2025-40918"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-294" ],
    "severity" : "CRITICAL",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-09-06T18:17:23Z"
  }
}