CVE-2026-4647

What it actually does

The flaw is an out-of-bounds read in the GNU Binutils BFD library when parsing specially crafted XCOFF object files. A relocation type value from the file is not sufficiently validated before being used, allowing BFD-consuming tools to read outside the intended bounds of an internal table or buffer. Practical impact is primarily process crash and denial of service for tools that inspect, link, transform, or analyze untrusted binary files; limited disclosure of process memory may also be possible depending on how the affected tool reports or exposes parsed data.

Why it matters to the business

Organizations that process third-party, user-submitted, downloaded, or automatically built binary artifacts could experience build failures, analysis pipeline crashes, CI/CD disruption, or instability in developer and security tooling. The confidentiality risk is lower than the availability risk, but memory exposure from binary-analysis tooling could leak limited sensitive data from the process context. Because GNU Binutils is widely embedded across Linux distributions, developer toolchains, container build systems, and downstream platforms such as Red Hat Enterprise Linux and OpenShift Container Platform, exposure may exist indirectly even where Binutils is not used as an end-user application.

How an attack unfolds

An attacker prepares a malformed XCOFF object file with a relocation type value crafted to trigger the insufficient bounds validation in the BFD parser. The attacker then causes a vulnerable Binutils-based utility or another application linked against BFD to process the file, typically by submitting it to a build system, artifact scanner, reverse-engineering workflow, source package, CI job, container build context, or analyst workstation. When the file is parsed, the vulnerable code reads beyond the expected memory bounds. The most likely outcome is a crash of the processing tool, interrupting the build or analysis workflow. In some circumstances, error output, diagnostics, generated metadata, or crash artifacts may expose limited memory contents from the affected process. The CVSS vector indicates local attack conditions and required user interaction, so exploitation generally requires convincing a user or automated workflow to process the crafted file rather than remote unauthenticated exploitation of a network service.

How to fix it

Upgrade GNU Binutils and operating system packages to vendor-fixed versions as they become available. No exact fixed versions were provided in the input, so use the security advisories and package repositories for the affected distribution or platform, including GNU Binutils, Red Hat Enterprise Linux, and Red Hat OpenShift Container Platform. Prioritize systems that process untrusted binaries, CI/CD runners, package builders, malware-analysis sandboxes, artifact scanners, and developer workstations. Where immediate patching is not possible, reduce exposure by blocking or quarantining untrusted XCOFF object files, disabling automatic processing of unfamiliar binary formats, running binary-analysis tools in isolated containers or sandboxes with resource limits, and preventing crash dumps from being world-readable or exported to less trusted systems.

How to confirm the fix worked

Confirm the installed Binutils package version is at or above the version identified as fixed by the relevant vendor advisory. Validate both standalone tools and embedded copies of libbfd used by other applications. On Linux systems, inventory packages with the native package manager and verify that libbfd and binutils binaries were updated together. Re-run any vendor-provided regression test or proof-of-concept test only in an isolated environment and confirm that the crafted XCOFF file is rejected or handled without crashing. For containerized environments, rebuild base images and CI runner images, then verify the updated package versions inside the running image rather than only on the host.

Typical attack path

1. Identify an environment or workflow that processes object files, archives, packages, container build inputs, or uploaded binaries using GNU Binutils/BFD-based tooling.
2. Create or obtain a specially crafted XCOFF object file with a malformed relocation type value.
3. Deliver the file through a repository, source package, attachment, artifact upload, CI/CD job, container build context, or other binary ingestion path.
4. Trigger processing by a vulnerable utility such as object inspection, symbol extraction, linking, stripping, copying, or automated artifact scanning.
5. Cause the BFD parser to perform an out-of-bounds read while handling the crafted relocation entry.
6. Achieve denial of service through tool crash and, in limited cases, obtain unintended memory content through diagnostics, output files, logs, or crash dumps.

How to detect it

Look for evidence that Binutils or BFD-linked tools processed unusual or untrusted XCOFF files and then crashed. Useful log sources include Linux audit logs, shell history, CI/CD job logs, package build logs, container build logs, artifact-scanning logs, systemd journal entries, core dump indexes, endpoint detection telemetry, and file upload records. Search for crashes or segmentation faults involving Binutils utilities such as objdump, readelf, nm, ld, objcopy, strip, ar, ranlib, size, addr2line, and tools known to use libbfd. Investigate jobs or user sessions where these tools handled files described as XCOFF, AIX object files, object archives, or unfamiliar binary object formats shortly before a crash. Review generated core dumps cautiously because they may contain sensitive process memory. Because there are no public exploit indicators or KEV listing in the provided data and EPSS is low, detection should focus on behavioral artifacts: malformed object file ingestion, repeated parser crashes, suspicious source/package submissions, and unexplained failures in automated binary-analysis or build workflows.

• libbfd
• XCOFF
• xcoff
• SIGSEGV
• segmentation fault
• core dumped
• objdump
• readelf
• nm
• ld
• objcopy
• strip
• ar
• ranlib
• size
• addr2line
• coredumpctl

What your security team should do

• Prioritize patching Binutils on build systems, CI/CD runners, artifact-processing services, package repositories, container build infrastructure, and security-analysis workstations.
• Inventory applications and appliances that embed or dynamically link against libbfd, not just systems with the binutils command-line package installed.
• Treat user-supplied object files, archives, source packages, and container build contexts as untrusted input; process them in sandboxed environments with least privilege and resource limits.
• Temporarily restrict automatic handling of XCOFF files where the format is not operationally required.
• Review crash dumps and diagnostic logs generated by Binutils-based tooling for possible sensitive memory exposure, and restrict access to those artifacts.
• Update base images and developer toolchain containers so patched Binutils versions are inherited by downstream builds.
• Monitor vendor advisories for Red Hat Enterprise Linux, Red Hat OpenShift Container Platform, and GNU Binutils for fixed package names and versions.