UAF in GNU ld (binutils) add_archive_element
CVE-2026-19548 Published on August 12, 2026

Binutils: binutils: multiple use-after-free in add_archive_element via lto plugin processing
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 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.

NVD

Vulnerability Analysis

CVE-2026-19548 is exploitable with local system access, requires user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.

Attack Vector:
LOCAL
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
REQUIRED
Scope:
UNCHANGED
Confidentiality Impact:
NONE
Integrity Impact:
NONE
Availability Impact:
HIGH

Timeline

Reported to Red Hat.

Made public. 63 days later.

Weakness Type

What is a Dangling pointer Vulnerability?

Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code.

CVE-2026-19548 has been classified to as a Dangling pointer vulnerability or weakness.


Products Associated with CVE-2026-19548

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Red Hat Enterprise Linux (RHEL)
 
Red Hat Hummingbird
 
Red Hat Openshift
 

Affected Versions

Red Hat Enterprise Linux 10: Red Hat Enterprise Linux 10: Red Hat Enterprise Linux 10: Red Hat Enterprise Linux 10: Red Hat Enterprise Linux 6: Red Hat Enterprise Linux 7: Red Hat Enterprise Linux 8: Red Hat Enterprise Linux 8: Red Hat Enterprise Linux 8: Red Hat Enterprise Linux 8: Red Hat Enterprise Linux 9: Red Hat Enterprise Linux 9: Red Hat Enterprise Linux 9: Red Hat Enterprise Linux 9: Red Hat Enterprise Linux 9: Red Hat Hardened Images: Red Hat OpenShift Container Platform 4: