IGEL OS 12 / 11 Secure Boot Bypass via Unsigned igel.conf File
IGEL OS 12 before 12.9.0, 12.8.3 LTS and IGEL OS 11 before 11.11.150 contain a secure boot bypass vulnerability in the GRUB boot stage that allows physically present attackers to gain unauthorized root access by placing an unsigned empty file named igel.conf on a partition. Attackers can exploit GRUB's fail-open signature verification behavior to drop into an interactive GRUB prompt, then boot the device's own kernel with additional command-line arguments to obtain a root shell with the disk unlocked while leaving TPM PCR values unaltered.
- Published
- Aug 28, 2026
- Updated
- Sep 24, 2026
- EPSS
- 0.3% · 15th percentile
- CWE
- CWE-636
Sign in to follow · You’ll be notified if a followed record enters KEV, gets an exploit or is updated.
Report tools
Action score
27
Monitor
Low priority for now.
- CVSS
- 27 / 40 · 6.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.3%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · VulnCheck
- 6.8
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Affected systems
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (VulnCheck). Independent of NVD's CPE analysis and usually ahead of it.
IGEL IGEL OS 11
- 11.0.0 and later · before 11.11.150affected · semver
IGEL IGEL OS 12
- 12.8.3, 12.9.0not affected
- 12.0.0 and later · up to and including 12.8.2affected · semver
Same product
igel: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-82017IGEL OS 12 / 11 Boot Registry Parameter Injection via Unsigned Configuration Area34Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| IGEL IGEL OS 11 | 11.11.150 | Vendor (CNA) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- Darren McDonaldAmberWolffinder
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Physical access to the device is required.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- Integrity
- Availability
- Attack vector
- Physical
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- X
Weakness class (CWE)
CWE-636 · Not Failing Securely ('Failing Open')CVSS vector
CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/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
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- blog.amberwolf.com/blog/2026/august/thin-client-thin-crypto-overview/
- kb.igel.com/en/security-safety/current/isn-2026-20-grub-shell-escape-in-igel-os
- media.defcon.org/DEF%20CON%2034/DEF%20CON%2034%20presentations/DEF%20CON%2034%20presentations/DEF%20CON%2034%20-%20Darren%20McDonald%20-%20Thin%20Client%20Thin%20Crypto%20-%20Bypassing%20Full-Desk%20Encryption%20Across%20Three%20Major%20Thin%20Clients%20Vendors%20without%20Breaking%20a%20Ci.pdf
- www.vulncheck.com/advisories/igel-os-12-11-secure-boot-bypass-via-unsigned-igel-conf-file
Vendor advisories and official records. Exploit/PoC links are deliberately left out.