CVE-2026-53424: Software Security Vulnerability Vulnerability

CRITICAL
Advisory Identifier: GHSA-5x87-gf34-8ww7
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CWE-294
Published
Advisory Summary

CVE-2026-53424 is a CRITICAL 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-2026-53424 at a Glance

CVE Identifier CVE-2026-53424
GHSA Identifier GHSA-5x87-gf34-8ww7
Severity CRITICAL
CVSS v3.1 Base Score N/A
CWE Classification CWE-294: Authentication Bypass by Capture-replay
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

How to Fix CVE-2026-53424

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-2026-53424, 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

Authentication Bypass by Capture-replay vulnerability in dropbox samly allows an attacker to authenticate as the subject of a captured SAML assertion by resubmitting it. Samly.Helper.decode_idp_auth_resp/3 in lib/samly/helper.ex calls esaml_sp:validate_assertion/2, whose default duplicate detector is a no-op. The /3 arity accepting a DuplicateFun exists in esaml and implements the check, but Samly never calls it and offers no configuration to supply one, so the SAML 2.0 Web Browser SSO Profile requirement that a bearer assertion be used once is unenforced. An attacker holding a valid SAMLResponse obtained from the network, from browser history, or from logs can submit the identical bytes repeatedly until the assertion's NotOnOrAfter passes, each time establishing a session as the assertion's subject. This issue affects samly: from v0.3.0 onward.

References

NVD — CVE-2026-53424 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-53424
cna.erlef.org/cves/cve-2026-53424... WEB
https://cna.erlef.org/cves/CVE-2026-53424.html
osv.dev/vulnerability/eef-c... WEB
https://osv.dev/vulnerability/EEF-CVE-2026-53424

Frequently Asked Questions

What is CVE-2026-53424?
CVE-2026-53424 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-2026-53424?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What CWE is associated with CVE-2026-53424?
CVE-2026-53424 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-2026-53424?
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-5x87-gf34-8ww7",
  "modified" : "2026-08-20T18:30:59Z",
  "published" : "2026-08-20T18:30:59Z",
  "aliases" : [ "CVE-2026-53424" ],
  "details" : "Authentication Bypass by Capture-replay vulnerability in dropbox samly allows an attacker to authenticate as the subject of a captured SAML assertion by resubmitting it.\n\nSamly.Helper.decode_idp_auth_resp/3 in lib/samly/helper.ex calls esaml_sp:validate_assertion/2, whose default duplicate detector is a no-op. The /3 arity accepting a DuplicateFun exists in esaml and implements the check, but Samly never calls it and offers no configuration to supply one, so the SAML 2.0 Web Browser SSO Profile requirement that a bearer assertion be used once is unenforced. An attacker holding a valid SAMLResponse obtained from the network, from browser history, or from logs can submit the identical bytes repeatedly until the assertion's NotOnOrAfter passes, each time establishing a session as the assertion's subject.\n\nThis issue affects samly: from v0.3.0 onward.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/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"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-53424"
  }, {
    "type" : "WEB",
    "url" : "https://cna.erlef.org/cves/CVE-2026-53424.html"
  }, {
    "type" : "WEB",
    "url" : "https://osv.dev/vulnerability/EEF-CVE-2026-53424"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-294" ],
    "severity" : "CRITICAL",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-08-20T18:16:27Z"
  }
}