CVE-2026-18220

Code execution via unchecked DLX relocation indexing

Published Jul 29, 2026 · Updated Jul 29, 2026

Out-of-bounds write in GNU binutils BFD DLX ELF backend allows local users to execute code by supplying a crafted ELF/DLX object. The dlx_rtype_to_howto() function lets arbitrary noncontiguous relocation values index dlx_elf_howto_table[] without an adequate bounds check. A BFD-consuming tool must process the object, and the build must include the DLX backend, typically through --enable-targets=all; successful exploitation runs code in that tool's context.

CVSS severity7.8
High
EPSS probability0.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in GNU binutils BFD DLX ELF backend allows local users to execute code by supplying a crafted ELF/DLX object. The dlx_rtype_to_howto() function lets arbitrary noncontiguous relocation values index dlx_elf_howto_table[] without an adequate bounds check. A BFD-consuming tool must process the object, and the build must include the DLX backend, typically through --enable-targets=all; successful exploitation runs code in that tool's context.

The record

CVE
CVE-2026-18220
Published
Jul 29, 2026
Updated
Jul 29, 2026
Vendor
389 Directory Server
Product
Red Hat Hardened Images
Classifications
CWE-787, T1203
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Jul 29, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 29, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

389 Directory Server · Red Hat Hardened ImagesAffected versions are unavailable in this record.

Published CVSS scores

7.8Red Hat, Inc.CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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