CVE-2026-19548
Received Received - Intake

Use-After-Free in GNU Binutils ld

Vulnerability report for CVE-2026-19548, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.

Publication date: 2026-08-12

Last updated on: 2026-08-12

Assigner: Red Hat, Inc.

Description

Multiple Use-After-Free vulnerabilities were found in the add_archive_element function in ld/ldmain.c of the GNU linker (ld), a component of binutils. The root cause is that plugin_maybe_claim() in ld/plugin.c frees the original BFD object via bfd_close/_bfd_delete_bfd when entry->the_bfd->my_archive == NULL, but the caller retains both the original abfd parameter and a shallow copy (orig_input.the_bfd) as dangling pointers. These dangling pointers are subsequently dereferenced at three distinct locations in add_archive_element: 1. Line ~1442: accessing abfd->my_archive via bfd_usrdata(abfd->my_archive) 2. Line ~1493: multiple accesses to abfd and abfd->my_archive in a conditional check and bfd_get_filename call 3. Line ~1525: dereferencing the shallow copy orig_input.the_bfd->my_archive in trace/verbose logging The vulnerability is triggered when LTO plugins are active (link_info.lto_plugin_active is true) and the input object has abfd->my_archive == NULL, which is a valid state for standalone object files. Red Hat builds binutils with --enable-plugins and --enable-lto, confirming the vulnerable code path is compiled in and reachable. An attacker who can supply a crafted object or archive file to a build process using LTO-enabled linking could exploit this flaw to cause a denial of service (linker crash via segmentation fault). Arbitrary code execution is theoretically possible through heap manipulation but is substantially mitigated by hardening measures including stack protector, FORTIFY_SOURCE, ASLR, and PIE. The attack surface is limited to build-time environments β€” the linker is a development tool not exposed in production runtime. The most realistic exploitation scenario is a supply chain attack introducing a crafted object file as a build dependency in CI/CD pipelines or development environments.

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Meta Information

Published
2026-08-12
Last Modified
2026-08-12
Generated
2026-08-12
AI Q&A
2026-08-12
EPSS Evaluated
N/A
NVD
EUVD

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
red_hat binutils From --enable-lto (inc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-416 The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Attack-Flow Graph

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Executive Summary

CVE-2026-19548 is a Use-After-Free vulnerability in the GNU linker (ld) component of binutils. It occurs in the add_archive_element function when LTO plugins are active. The issue arises when plugin_maybe_claim() frees a BFD object but retains dangling pointers. These pointers are later dereferenced, causing crashes or potential code execution.

Detection Guidance

Detecting this vulnerability requires checking if your system uses binutils with LTO and plugin support enabled. Inspect binutils version and configuration with: ld --version and grep for plugin/LTO flags in build logs. Monitor linker crashes during builds, especially with segmentation faults in ld.

Impact Analysis

The primary impact is a denial of service via linker crashes during build processes using LTO-enabled linking. Arbitrary code execution is possible but unlikely due to system hardening. The attack surface is limited to build-time environments, making supply chain attacks in CI/CD pipelines the main risk.

Mitigation Strategies

Disable LTO and plugin support in binutils builds. Avoid linking untrusted object/archive files. Update binutils to patched versions when available. Monitor Red Hat advisories for fixes. Restrict build environments to trusted inputs.

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