Cyber Resilience

CVE-2026-63277

Published
05 October 2026
Modified
06 October 2026
CVSS Score v4 8.5
Click a component to see what it means
Raw vectorCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/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
EPSS Score 0.0015 4th percentile
Risk Priority 55 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-63277 is a high-severity Inclusion of Functionality from Untrusted Control Sphere (CWE-829) vulnerability in Libreoffice (inferred from references). Its CVSS base score is 8.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Software Extensions (T1176); ranked at the 4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SR-3 (Supply Chain Controls and Processes) and SR-4 (Provenance) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A08:2025 Software or Data Integrity Failures

EU & UK References

Vulnerability Data

LibreOffice Calc can link a cell range to an external data source, and the link is saved in the document. A document could name a Java database driver for such a link to be loaded from a remote location, so…

more

opening the document could run Java code from that location. In fixed versions an entry in a Java class path has to be a file URL.

CWE(s)
CWE-829

Related Threats

MITRE ATT&CK Enterprise Techniques

T1176 Software Extensions Persistence
Adversaries may abuse software extensions to establish persistent access to victim systems.
attack.mitre.org →
T1195.001 Compromise Software Dependencies and Development Tools Initial Access
Adversaries may manipulate software dependencies and development tools prior to receipt by a final consumer for the purpose of data or system compromise.
attack.mitre.org →
T1055 Process Injection Stealth
Adversaries may inject code into processes in order to evade process-based defenses as well as possibly elevate privileges.
attack.mitre.org →
T1195 Supply Chain Compromise Initial Access
Adversaries may manipulate products or product delivery mechanisms prior to receipt by a final consumer for the purpose of data or system compromise.
attack.mitre.org →
T1505.004 IIS Components Persistence
Adversaries may install malicious components that run on Internet Information Services (IIS) web servers to establish persistence.
attack.mitre.org →
T1505.005 Terminal Services DLL Persistence
Adversaries may abuse components of Terminal Services to enable persistent access to systems.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-43571Shared CWE-829
CVE-2025-53546Shared CWE-829
CVE-2026-40959Shared CWE-829
CVE-2023-45798Shared CWE-829
CVE-2025-62186Shared CWE-829
CVE-2024-52976Shared CWE-829
CVE-2025-0982Shared CWE-829
CVE-2025-36727Shared CWE-829
CVE-2026-15560Shared CWE-829
CVE-2026-18408Shared CWE-829

Affected Assets

Libreoffice
—
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 6 hardening rules · 6 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V14.2.3
  • V3.5.6
  • V9.1.3
  • V15.3.2

Mitigating Controls (NIST 800-53 r5) AI

SR-3 Supply Chain Controls and Processes partial match

Establishes processes to identify and address supply-chain weaknesses that would allow untrusted functionality.

SR-4 Provenance partial match

Requires documented, valid provenance for components, preventing acceptance of code from outside the trusted sphere.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

GV.SC-01 partial match
blocks

Supply-chain program directly governs inclusion of third-party executable code.

GV.SC-05 partial match
blocks

Contractual requirements can mandate trusted sources and integrity checks for included functionality.

GV.SC-07 partial match
blocks

Supplier risk assessment explicitly covers risks from their products and libraries.

ID.AM-02 partial match
blocks

Software inventory enables tracking of externally sourced components but does not itself enforce trust.

ID.RA-09 partial match
blocks

Pre-acquisition integrity/authenticity checks directly prevent inclusion of untrusted code.

ID.RA-10 partial match
blocks

Critical-supplier assessment reduces risk of importing executable functionality from untrusted parties.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.5.14 Information transfer partial match
removes
A.5.15 Access control partial match
removes
A.5.16 Identity management partial match
removes
A.5.17 Authentication information partial match
removes
A.5.18 Access rights partial match
removes
A.5.21 Managing information security in the ICT supply chain partial match
blocks

A.5.21's requirements to define/propagate security needs, obtain component origin/trust assurances, validate delivered products (incl. via testing), ensure genuine/unaltered components, and manage lifecycle directly stop most untrusted inclusion by shrinking the untrusted sphere before integration; bounded remainder exists for custom or insider-introduced functionality the clause does not reach.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (higher-evidence rows only; rows rated `none` are excluded).

Oracle Linux 8 (1 rule)
  • V-248635 Executable search paths within the initialization files of all local interactive OL 8 users must only contain paths that resolve to the system default or the user's home directory. blocks CWE-829
Oracle Linux 9 (1 rule)
  • V-271847 OL 9 must be configured so that executable search paths within the initialization files of all local interactive users must only contain paths that resolve to the system default or the users home directory. blocks CWE-829
RHEL 7 (1 rule)
  • V-204477 The Red Hat Enterprise Linux operating system must be configured so that all local interactive user initialization files executable search paths contain only paths that resolve to the users home directory. blocks CWE-829
RHEL 8 (1 rule)
  • V-230317 Executable search paths within the initialization files of all local interactive RHEL 8 users must only contain paths that resolve to the system default or the users home directory. blocks CWE-829
RHEL 9 (1 rule)
  • V-258050 Executable search paths within the initialization files of all local interactive RHEL 9 users must only contain paths that resolve to the system default or the users home directory. blocks CWE-829
Windows 10 (1 rule)
  • V-220737 Administrative accounts must not be used with applications that access the Internet, such as web browsers, or with potential Internet sources, such as email. blocks CWE-829

References