GHSA-J77F-3FFJ-4JG4
Vulnerability from github – Published: 2026-08-12 18:31 – Updated: 2026-08-12 18:31Multiple 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:
- Line ~1442: accessing abfd->my_archive via bfd_usrdata(abfd->my_archive)
- Line ~1493: multiple accesses to abfd and abfd->my_archive in a conditional check and bfd_get_filename call
- 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.
{
"affected": [],
"aliases": [
"CVE-2026-19548"
],
"database_specific": {
"cwe_ids": [
"CWE-416"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-12T16:16:55Z",
"severity": "MODERATE"
},
"details": "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-\u003ethe_bfd-\u003emy_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:\n\n1. Line ~1442: accessing abfd-\u003emy_archive via bfd_usrdata(abfd-\u003emy_archive)\n2. Line ~1493: multiple accesses to abfd and abfd-\u003emy_archive in a conditional check and bfd_get_filename call\n3. Line ~1525: dereferencing the shallow copy orig_input.the_bfd-\u003emy_archive in trace/verbose logging\n\nThe vulnerability is triggered when LTO plugins are active (link_info.lto_plugin_active is true) and the input object has abfd-\u003emy_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.\n\nAn 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.\n\nThe attack surface is limited to build-time environments \u2014 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.",
"id": "GHSA-j77f-3ffj-4jg4",
"modified": "2026-08-12T18:31:17Z",
"published": "2026-08-12T18:31:17Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-19548"
},
{
"type": "WEB",
"url": "https://access.redhat.com/security/cve/CVE-2026-19548"
},
{
"type": "WEB",
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2507832"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.