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NVD / CVE Program· CNA certcc

CVE-2026-8863: Multiple Microsoft-sigend UEFI SHIM bootloaders are vulnerable to SecureBoot bypass.

Noroxi assessment

Priority: Monitor (action score 31/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.11% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Windows 10 Version 1607 for 32-bit Systems 10.0.14393.9234; Windows 10 Version 1607 for x64-based Systems 10.0.14393.9234; Windows 10 Version 1809 for 32-bit Systems 10.0.17763.8880.

Low priority for now. Upgrade to Windows 10 Version 1607 for 32-bit Systems 10.0.14393.9234; Windows 10 Version 1607 for x64-based Systems 10.0.14393.9234; Windows 10 Version 1809 for 32-bit Systems 10.0.17763.8880 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Multiple Microsoft-sigend UEFI SHIM bootloaders are vulnerable to SecureBoot bypass. An attacker with administrative privileges or the ability to modify the boot process could use one of the vulnerable shim bootloaders to bypass Secure Boot protections and execute arbitrary code before the operating system loads. Specific UEFI DBX update is required to block these vulnerable boot loaders.

HighCVSS 7.8 · v3.1—Proof of concept Fix available
Published
Jun 9, 2026
Updated
Jul 23, 2026
EPSS
0.1% · 1th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • Proof of concept exists, no weaponized module
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-8863

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (certcc). Independent of NVD's CPE analysis and usually ahead of it.

  • baramundi software baramundi Management Suite

    • up to and including 2024R1affected

  • Blancco UK WhiteCanyon WipeDrive

    • 8.0.0 and later · up to and including 8.1.3affected

  • Finland Matriculation Board Abitti 1

    • 1.0.0affected

  • NTC IT ROSA LLC RosaLinux

    • R9, R10affected

  • Oracle Corporation OracleLinux(7.2) shim

    • 0.9affected

  • PC-Doctor Factory for Linux (Bootable Diagnostics)

    • 6.9 and later · up to and including 6.20.7710.267affected

  • PC-Doctor Network Factory for Linux (Bootable Diagnostics)

    • 6.9 and later · up to and including 6.20.7711.267affected

  • PC-Doctor Service Center

    • 14 and later · up to and including 17.0.7535.900affected

  • PC-Doctor Service Center Drive Erase

    • 15 and later · up to and including 17.0.7538.592affected

  • PC-Doctor Service Center Enterprise

    • 14 and later · up to and including 17.0.7536.900affected

  • PC-Doctor Service Center Japan

    • 15 and later · up to and including 17.0.7539.904affected

  • Spyrus WTGCreator

    • 4.2affected

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Windows 10 Version 1607 for 32-bit Systems10.0.14393.9234 · KB5094122Microsoft (MSRC)
Windows 10 Version 1607 for x64-based Systems10.0.14393.9234 · KB5094122Microsoft (MSRC)
Windows 10 Version 1809 for 32-bit Systems10.0.17763.8880 · KB5094123Microsoft (MSRC)
Windows 10 Version 1809 for x64-based Systems10.0.17763.8880 · KB5094123Microsoft (MSRC)
Windows 10 Version 21H2 for 32-bit Systems10.0.19044.7417 · KB5094127Microsoft (MSRC)
Windows 10 Version 21H2 for ARM64-based Systems10.0.19044.7417 · KB5094127Microsoft (MSRC)
Windows 10 Version 21H2 for x64-based Systems10.0.19044.7417 · KB5094127Microsoft (MSRC)
Windows 10 Version 22H2 for 32-bit Systems10.0.19045.7417 · KB5094127Microsoft (MSRC)
Windows 10 Version 22H2 for ARM64-based Systems10.0.19045.7417 · KB5094127Microsoft (MSRC)
Windows 10 Version 22H2 for x64-based Systems10.0.19045.7417 · KB5094127Microsoft (MSRC)
Windows 11 Version 23H2 for ARM64-based Systems10.0.22631.7219 · KB5093998Microsoft (MSRC)
Windows 11 Version 23H2 for x64-based Systems10.0.22631.7219 · KB5093998Microsoft (MSRC)
Windows 11 Version 24H2 for ARM64-based Systems10.0.26100.8655 · KB5094126Microsoft (MSRC)
Windows 11 Version 24H2 for x64-based Systems10.0.26100.8655 · KB5094126Microsoft (MSRC)
Windows 11 Version 25H2 for ARM64-based Systems10.0.26200.8655 · KB5094126Microsoft (MSRC)
Windows 11 Version 25H2 for x64-based Systems10.0.26200.8655 · KB5094126Microsoft (MSRC)
Windows 11 Version 26H1 for ARM64-based Systems10.0.28000.2269 · KB5095051Microsoft (MSRC)
Windows 11 version 26H1 for x64-based Systems10.0.28000.2269 · KB5095051Microsoft (MSRC)
Windows Server 20126.2.9200.26132 · KB5094042Microsoft (MSRC)
Windows Server 2012 (Server Core installation)6.2.9200.26132 · KB5094042Microsoft (MSRC)
Windows Server 2012 R26.3.9600.23228 · KB5094041Microsoft (MSRC)
Windows Server 2012 R2 (Server Core installation)6.3.9600.23228 · KB5094041Microsoft (MSRC)
Windows Server 201610.0.14393.9234 · KB5094122Microsoft (MSRC)
Windows Server 2016 (Server Core installation)10.0.14393.9234 · KB5094122Microsoft (MSRC)
Windows Server 201910.0.17763.8880 · KB5094123Microsoft (MSRC)
Windows Server 2019 (Server Core installation)10.0.17763.8880 · KB5094123Microsoft (MSRC)
Windows Server 202210.0.20348.5256 · KB5094128Microsoft (MSRC)
Windows Server 2022 (Server Core installation)10.0.20348.5256 · KB5094128Microsoft (MSRC)
Windows Server 202510.0.26100.32995 · KB5094125Microsoft (MSRC)
Windows Server 2025 (Server Core installation)10.0.26100.32995 · KB5094125Microsoft (MSRC)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:12026-07-21

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.

  1. Published
  2. First PoC+41 d
  3. TodayOct 30, 2026+143 d

No history yet (it accumulates with the daily EPSS job).

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 researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

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

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-347 · Improper Verification of Cryptographic Signature

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-secondary

Root cause

The verifier takes the algorithm to verify with from the token’s own header. Untrusted data ends up deciding its own verification rule.

The bug in code

The whole CWE-347 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

ts
const claims = jwt.verify(token, publicKey);

Fixed

ts
const claims = jwt.verify(token, publicKey, {  algorithms: ["RS256"],  issuer: "https://id.example.com",  audience: "portal",});

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records