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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-18220 Detail

Description

An out-of-bounds write vulnerability was found in the BFD library's DLX ELF backend (bfd/elf32-dlx.c) in GNU binutils. The dlx_rtype_to_howto() function maps ELF relocation types to internal howto structures but fails to perform adequate bounds checking on attacker-controlled relocation type values (via ELF32_R_TYPE(r_info)) before indexing into the dlx_elf_howto_table[] array. The DLX relocation type number space is non-contiguous (basic types 0-6, extended types at 0x10000+), but the default case in the switch statement allows arbitrary index values to reach the array access. A specially crafted ELF/DLX object file can trigger this out-of-bounds write when processed by any BFD-consuming tool (objdump, readelf, strip, ld, nm, objcopy). The vulnerability has been demonstrated to achieve arbitrary code execution via a File Stream Oriented Programming (FSOP) attack against glibc FILE structures (stderr), redirecting control flow to system(). Attack scenarios include CI/CD pipelines performing automated binary analysis, developer workstations running objdump/readelf on untrusted binaries, automated security scanning or malware analysis tools invoking binutils, and package build systems processing third-party code. Note: This vulnerability is only exploitable when binutils is built with the DLX backend enabled (typically via --enable-targets=all).


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

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URL Source(s) Tag(s)
https://access.redhat.com/security/cve/CVE-2026-18220 Red Hat, Inc.
https://bugzilla.redhat.com/show_bug.cgi?id=2507670 Red Hat, Inc.

Weakness Enumeration

CWE-ID CWE Name Source
CWE-787 Out-of-bounds Write Red Hat, Inc.  

Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-18220
NVD Published Date:
07/29/2026
NVD Last Modified:
07/29/2026
Source:
Red Hat, Inc.