CVE
gittuf authorization bypass in namespace policy verification
- Exploited
- No known exploitation
- Fix
- Fixed in 0.16.0
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 0.16.0.
- Published
- Last modified
- Whether it needs action now or is a reference record, by fixed rules, with why. Last checked is when cve.now last re-read it.What do these mean? →
- Reference
- Last checked
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 20/100 · provisional
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
gittuf, a tool for securing Git repositories, has a flaw where a global minimum-threshold rule takes precedence over a policy rule covering the same namespace during verification. Remotely, by an attacker with low-privilege login and no user action, a user who is not authorized by the policy rule, or who is one of fewer users than its threshold, can make changes to the protected namespace that pass verification, which can compromise the integrity of that data.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
Read the original description
In gittuf 0.10.0 through 0.15.0, when a minimum threshold global rule and a policy rule protect the same namespace, verification gives the global rule's check over all trusted users in the policy precedence over the policy rule's own authorized users. A user listed in the policy file but not authorized by the policy rule, or fewer users than the rule's threshold, can make changes to the protected namespace that pass verification.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure3/25Reachable over the network · Unknown: No advisory context yet
- Reach10/20Affects Go packages
- Severity6.5/10CVSS 6.5
- No patch0/5No signal
What would change the score
- Would score about 75 if added to CISA KEV
- Would score about 70 if CISA's SSVC rates exploitation active
- Would score about 39 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 0.16.0.
Check your systems with an agent
Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.
Check whether my systems are affected by CVE-2026-128037 (gittuf: Policy rules bypassed in the presence of global rules), using the cve.now data below.
Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.
What cve.now has for CVE-2026-128037 (entry last updated 2026-11-13):
Affected:
- Go package github.com/gittuf/gittuf: from 0.10.0, fixed in 0.16.0
Fixed versions: 0.16.0.
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
CISA KEV: CVE-2026-128037 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-128037 only. If you also check another CVE, look up its own KEV status; never assume it from this one.
How to check:
- Packages (Go): find every lockfile in each project and run the stack.check operation of the cve.now MCP server (execute) on each one. Compare the resolved versions, not the ranges a manifest declares, with the affected versions above. Include transitive dependencies.
Verify against the linked advisories before concluding, and cite the date you read each one:
- https://github.com/gittuf/gittuf/security/advisories/GHSA-qc8j-pcph-6q9x
- https://github.com/gittuf/gittuf/releases/tag/v0.16.0
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.
Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.
Entry: https://cve.now/CVE-2026-128037
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example execute with name cve.get and arguments {"id": "CVE-2026-128037"}.Timeline
- CVE published
- First seen by cve.now
Affected versions
From 0.10.0 · fixed in 0.16.0
Evidence 4
Vendor advisory · 1
Establishes: Affected and fixed versions.
- Advisory
CVE record · 2
Establishes: The identifier and description.
- Record
- Record
Other links · 1
- Repository
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-128037
Is CVE-2026-128037 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
Which versions are affected by CVE-2026-128037?
github.com/gittuf/gittuf (Go): from 0.10.0 before 0.16.0.Source: cve.now feed data
How do I fix CVE-2026-128037?
Upgrade to a fixed version: 0.16.0.Source: cve.now feed data