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TI-2026-21580 Aliases CVE-2026-27129GHSA-v2gc-rm6g-wrw9

Cloud Metadata SSRF Protection Bypass via IPv6 Resolution

Priority LOW 34CWE-918Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
—
Confidentiality · integrity · availability
None · High · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub.

Summary

Craft is a content management system (CMS). In versions 4.5.0-RC1 through 4.16.18 and 5.0.0-RC1 through 5.8.22, the SSRF validation in Craft CMS’s GraphQL Asset mutation uses `gethostbyname()`, which only resolves IPv4 addresses. When a hostname has only AAAA (IPv6) records, the function returns the hostname string itself, causing the blocklist comparison to always fail and completely bypassing SSRF protection. This is a bypass of the security fix for CVE-2025-68437. Exploitation requires GraphQL schema permissions for editing assets in the `<VolumeName>` volume and creating assets in the `<VolumeName>` volume. These permissions may be granted to authenticated users with appropriate GraphQL schema access and/or Public Schema (if misconfigured with write permissions). Versions 4.16.19 and 5.8.23 patch the issue.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00464 40th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed cms (craftcms): 4.16.19, 5.8.23craftcms/cms (Packagist): 5.8.23, 4.16.19

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
Craft CMScms4.5.0-RC1 to before 4.16.19; 5.0.0-RC1 to before 5.8.234.16.19, 5.8.23Patch availableCNA
—craftcms/cms (Packagist)5.0.0-RC1 to before 5.8.235.8.23Patch availableGHSA-v2gc-rm6g-wrw9
—craftcms/cms (Packagist)3.5.0 to before 4.16.194.16.19Patch availableGHSA-v2gc-rm6g-wrw9
  • cms VendorCraft CMS Affected 4.5.0-RC1 to before 4.16.19; 5.0.0-RC1 to before 5.8.23 Fixed in 4.16.19, 5.8.23 Patch available CNA
  • craftcms/cms (Packagist) Vendor— Affected 5.0.0-RC1 to before 5.8.23 Fixed in 5.8.23 Patch available GHSA-v2gc-rm6g-wrw9
  • craftcms/cms (Packagist) Vendor— Affected 3.5.0 to before 4.16.19 Fixed in 4.16.19 Patch available GHSA-v2gc-rm6g-wrw9

CPE configurations NVD · 3

CPEVersionsRoleVendor
cpe:2.3:a:craftcms:craft_cms:*:*:*:*:*:*:*:*3.5.0 to before 4.16.19; 5.0.1 to before 5.8.23VulnerableCraft CMS
cpe:2.3:a:craftcms:craft_cms:5.0.0:-:*:*:*:*:*:*5.0.0VulnerableCraft CMS
cpe:2.3:a:craftcms:craft_cms:5.0.0:rc1:*:*:*:*:*:*5.0.0 rc1VulnerableCraft CMS
  • cpe:2.3:a:craftcms:craft_cms:*:*:*:*:*:*:*:* Versions 3.5.0 to before 4.16.19; 5.0.1 to before 5.8.23 Vulnerable ·Craft CMS
  • cpe:2.3:a:craftcms:craft_cms:5.0.0:-:*:*:*:*:*:* Versions 5.0.0 Vulnerable ·Craft CMS
  • cpe:2.3:a:craftcms:craft_cms:5.0.0:rc1:*:*:*:*:*:* Versions 5.0.0 rc1 Vulnerable ·Craft CMS

Remediation

  • Fix · CNA cms (craftcms) Fixed in 4.16.19, 5.8.23
  • Fix · GHSA-v2gc-rm6g-wrw9 craftcms/cms (Packagist) Fixed in 5.8.23 Advisory →
  • Fix · GHSA-v2gc-rm6g-wrw9 craftcms/cms (Packagist) Fixed in 4.16.19 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-27129
  2. 2026-10-03 Alias added: GHSA-v2gc-rm6g-wrw9

References

Exploit 1

Patch 1

Advisory 1

Other 2

  • TI-2025-23503 Craft CMS Allows Remote Code Execution KEVCVSS 3.1CRITICAL 10.0
  • TI-2024-37138 RCE when PHP `register_argc_argv` config setting is enabled in craftcms/cms KEVCVSS 4.0CRITICAL 9.3
  • TI-2025-16994 Potential RCE with a compromised security key in craft/cms KEVCVSS 3.1HIGH 8.1
  • TI-2025-24595 Craft CMS stores user-provided content in session files KEVCVSS 4.0MEDIUM 6.9
  • TI-2023-22284 Craft CMS Remote Code Execution vulnerability CVSS 3.1CRITICAL 10.0
  • TI-2024-25171 Craft CMS up to v3.7.31 was discovered to contain a SQL injection vulnerability via the GraphQL API endpoint. CVSS 3.1CRITICAL 9.8
See all 96 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences