Summary
Nginx UI: Backup restore follows crafted symlinks into the live Nginx configuration path before restore flags are applied
An authenticated user who can create and restore a backup can craft a valid backup archive that causes the restore staging process to write attacker-controlled files into the live Nginx configuration path even when both restore_nginx and restore_nginx_ui are set to false.
Details
The restore flow always extracts the outer archive, verifies the manifest, decrypts nginx-ui.zip and nginx.zip, and extracts both inner archives before it decides whether RestoreNginx or RestoreNginxUI should be applied. The zip extractor explicitly allows absolute symlinks when the link target is under nginx.GetConfPath() or nginx.GetModulesPath(). Later regular-file entries are then created with os.OpenFile() on the symlinked path, which follows the symlink and writes into the live path.
Relevant code paths:
- internal/backup/restore.go
- internal/backup/restore.go
- internal/backup/restore.go
- internal/backup/restore.go
- api/backup/restore.go
- api/backup/backup.go
This means the restore trust boundary is broken during extraction. A restore request that explicitly opted out of restoring either Nginx or Nginx UI can still modify the live Nginx configuration tree during staging.
PoC
I verified this locally in an isolated environment with a temporary package-level harness that exercised the real Backup() and Restore() implementations.
What the executed test did:
- Created a temporary
app.ini, database file, and a temporary live Nginx config directory. - Called the real
Backup()implementation to obtain a valid backup archive plus AES key/IV. - Extracted the outer backup, decrypted
nginx.zip, replaced it with a crafted zip containing:- a symlink entry
link -> <live nginx conf dir> - a later regular file entry
link/poc.conf
- a symlink entry
- Recomputed
manifest.jsonsize/hash values for the modified encryptednginx.zipand re-signedmanifest.sigwith the expected signing key derived from the AES key. - Repacked the outer archive and called the real
Restore()implementation with:RestoreNginx: falseRestoreNginxUI: false
- Verified that
<live nginx conf dir>/poc.confwas created anyway.
Observed result from the actual local verification:
- The crafted restore completed successfully with both restore flags set to
false. - The asserted sink was the existence and content of the live-path file written during restore staging.
Impact
Any deployment that allows an authenticated user to create and restore backups is affected. A crafted restore archive can modify the live Nginx configuration path before either restore toggle is honored. This can lead to persistent configuration injection, denial of service on a later reload, or other follow-on impact depending on what files the deployment later consumes from the modified path.
CVE-2026-107810 has a CVSS score of 8.1 (High). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.9.10-0.20260728074146-a467ed652591); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2026-107810? CVE-2026-107810 is a high-severity security vulnerability in github.com/0xJacky/Nginx-UI (go), affecting versions >= 1.9.10-0.20250517140552-daee3ac7ade1, < 1.9.10-0.20260728074146-a467ed652591. It is fixed in 1.9.10-0.20260728074146-a467ed652591.
- How severe is CVE-2026-107810? CVE-2026-107810 has a CVSS score of 8.1 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of github.com/0xJacky/Nginx-UI are affected by CVE-2026-107810? github.com/0xJacky/Nginx-UI (go) versions >= 1.9.10-0.20250517140552-daee3ac7ade1, < 1.9.10-0.20260728074146-a467ed652591 is affected.
- Is there a fix for CVE-2026-107810? Yes. CVE-2026-107810 is fixed in 1.9.10-0.20260728074146-a467ed652591. Upgrade to this version or later.
- Is CVE-2026-107810 exploitable, and should I be worried? Whether CVE-2026-107810 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-107810 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-107810? Upgrade
github.com/0xJacky/Nginx-UIto 1.9.10-0.20260728074146-a467ed652591 or later.