Review reviewHigh

CVE-2026-56233

Capgo

Capgo before 12.128.2 contains a path traversal vulnerability in the builder upload proxy that allows authenticated users with build permissions to bypass upload restrictions. Attackers can append traversal sequences to the upload path, which are normalized by the WHATWG URL parser, enabling access to internal administrative endpoints with the privileged BUILDER_API_KEY header and resulting in server-side privilege escalation.

CVSS
8.7
EPSS
0.45%
36.5% percentile
CISA KEV
Not listed
Published
2026.07.01
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.45%
Technical severityCVSS 8.7

Vulnerability overview

Capgo before 12.128.2 contains a path traversal vulnerability in the builder upload proxy that allows authenticated users with build permissions to bypass upload restrictions. Attackers can append traversal sequences to the upload path, which are normalized by the WHATWG URL parser, enabling access to internal administrative endpoints with the privileged BUILDER_API_KEY header and resulting in server-side privilege escalation.

Affected product and versions

Product
Capgo
Affected versions
See the vendor advisory and NVD configuration data
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Capgo and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/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
CWE
CWE-22