CVE-2026-19582: Binutils Buffer Overflow Vulnerability

CVE-2026-19582 Overview

CVE-2026-19582 is a stack buffer overflow out-of-bounds write vulnerability in GNU Binutils version 2.46.1 and prior. The flaw resides in the PE (Portable Executable) file parsing logic used across the Binutils toolchain. A user who opens a crafted PE file with a Binutils utility can trigger arbitrary code execution in the context of the invoked process. Exploitation requires local file access and user interaction, but no prior authentication. The weakness is tracked under CWE-787 (Out-of-bounds Write).

Critical Impact
A crafted PE file processed by Binutils utilities such as objdump, readelf, or nm can overwrite the stack and execute attacker-controlled code with the privileges of the invoking user.

Affected Products

GNU Binutils version 2.46.1
All GNU Binutils versions prior to 2.46.1
Linux distributions redistributing vulnerable Binutils packages (see Red Hat CVE-2026-19582 Advisory)

Discovery Timeline

2026-08-20 - CVE-2026-19582 published to the National Vulnerability Database
2026-08-20 - Last updated in NVD database

Technical Details for CVE-2026-19582

Vulnerability Analysis

The vulnerability is a stack-based out-of-bounds write in the PE file parser shipped with GNU Binutils. Binutils components such as objdump, readelf, nm, and addr2line share common BFD (Binary File Descriptor) library routines to parse object files. When one of these tools processes a PE file whose headers or section descriptors contain manipulated size or offset fields, the parser writes past the bounds of a fixed-size stack buffer.

Because the corruption occurs on the stack, an attacker who controls the overflowing bytes can overwrite saved return addresses, stack canaries (if unprotected builds are used), or adjacent local variables. The result is arbitrary code execution in the same security context as the user running the Binutils tool. This is a local attack vector, so exploitation typically occurs through supply-chain paths such as malicious build artifacts, reverse-engineering targets, or automated CI pipelines that invoke Binutils on untrusted binaries.

Root Cause

The defect stems from missing bounds validation on length or offset fields read directly from the PE file header structures. The parser trusts attacker-controlled values when copying data into a stack buffer, satisfying the conditions of [CWE-787]. Refer to the Red Hat Bug Report #2513754 for upstream analysis.

Attack Vector

An attacker crafts a malformed PE file and delivers it to a target through email, a shared repository, a container image, or a compromised build artifact. When a developer, reverse engineer, or automated pipeline invokes any Binutils utility against the file, the parser executes attacker-supplied shellcode or ROP chains. No network exposure is required, and no privileges are needed beyond the ability to deliver the file.

No verified public proof-of-concept is available at the time of publication.
See the Red Hat advisory linked above for upstream technical details.

Detection Methods for CVE-2026-19582

Indicators of Compromise

Crashes or segmentation faults produced by objdump, readelf, nm, or addr2line when processing PE files
Unexpected child processes spawned by Binutils utilities, particularly shells or network clients
PE files with malformed section tables, oversized header fields, or invalid NumberOfSections values arriving through untrusted channels
Core dumps from Binutils processes containing non-standard return addresses on the stack

Detection Strategies

Monitor process execution telemetry for Binutils binaries invoking non-standard children such as /bin/sh, bash, curl, or wget
Deploy YARA rules that flag PE files with inconsistent header sizes or overlapping section descriptors staged in developer or CI environments
Correlate Binutils crash events across build hosts to identify systemic exposure to malformed inputs

Monitoring Recommendations

Enable auditd or equivalent syscall auditing on build and analysis systems that regularly invoke Binutils
Log all PE files introduced into CI/CD pipelines and reverse-engineering sandboxes with hash-based provenance
Alert on Binutils processes generating core dumps, particularly when triggered by files from external sources

How to Mitigate CVE-2026-19582

Immediate Actions Required

Inventory all systems running GNU Binutils 2.46.1 or earlier, including developer workstations, build servers, and container base images
Restrict execution of Binutils tools against untrusted PE files until patched packages are deployed
Apply distribution-provided updates as they become available; monitor the Red Hat CVE-2026-19582 Advisory for downstream package releases

Patch Information

At publication time, downstream vendors are tracking the issue through advisories such as Red Hat Bug Report #2513754. Upgrade to a Binutils release later than 2.46.1 once available from the upstream GNU project or your Linux distribution. Rebuild any statically linked toolchains that embed vulnerable BFD code.

Workarounds

Run Binutils tools inside sandboxes such as firejail, bubblewrap, or ephemeral containers with no network access and minimal filesystem privileges
Route all untrusted binary analysis through dedicated, non-privileged accounts on isolated hosts
Enforce file-type allowlists in CI pipelines to reject unexpected PE files before Binutils is invoked
Ensure Binutils is compiled with stack protectors, -D_FORTIFY_SOURCE=2, and position-independent executables to raise exploitation cost

bash

# Example: sandbox objdump execution with bubblewrap
bwrap --ro-bind /usr /usr --ro-bind /lib /lib --ro-bind /lib64 /lib64 \
      --bind /tmp/analysis /work --chdir /work --unshare-all \
      /usr/bin/objdump -x suspicious.exe