Bug 2508330 - CVE-2026-18220 insight: binutils: Out-of-bounds write in BFD DLX ELF backend relocation processing [fedora-all]
Summary: CVE-2026-18220 insight: binutils: Out-of-bounds write in BFD DLX ELF backend ...
Keywords:
Status: CLOSED NOTABUG
Alias: None
Product: Fedora
Classification: Fedora
Component: insight
Version: rawhide
Hardware: Unspecified
OS: Unspecified
high
high
Target Milestone: ---
Assignee: Patrick Monnerat
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard: {"flaws": ["503aed4c-c1d5-4ba2-b01e-0...
Depends On:
Blocks: CVE-2026-18220
TreeView+ depends on / blocked
 
Reported: 2026-07-29 10:01 UTC by Samuele Negrini
Modified: 2026-08-07 18:54 UTC (History)
1 user (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed: 2026-08-07 18:54:53 UTC
Type: ---
Embargoed:


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Description Samuele Negrini 2026-07-29 10:01:00 UTC
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

*** This is a vulnerability report sent to us through https://issues.redhat.com/browse/PSIRTSUPT-18741 and was created using the PoC auto-triage agents. It contains hints on the vulnerability extracted by the IA and the full report. ALWAYS review it before any action. Once working on this, don't forget to also update the JSM ticket. ***

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). Manual verification of Red Hat package build configurations is required to confirm affected product scope.

Comment 1 Patrick Monnerat 2026-08-07 18:54:53 UTC
This CVE is nothing else but AI delirium. It should have been triaged by the reporter.
Should it be an OOB write vulnerability for dlx architecture, the only serious report is https://github.com/4D4J/objdump-Out-Of-Bounds-write and linked commit for a fix.

In all cases, the dlx architecture is not supported/compiled-in, thus closing as not a bug.


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