CVE catalog

CVE-2026-18220

Severity: High · CVSS 7.8CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Published: Jul 29, 2026, 9:42:36 AM UTC
Source: [NVD] · [CVE record]
EPSS: 0.19% · Oct 25, 2026

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).

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	binutils	sid	`2.47.50.20261021-1`	vulnerable
Debian	binutils	forky	`2.47.50.20261021-1`	vulnerable
Debian	binutils	trixie	`2.44-3`	vulnerable
Debian	binutils	bookworm	`2.40-2`	vulnerable

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	binutils	source	sid	`(unfixed)`	unimportant	Not reported	Not reported
Debian	binutils	source	forky	`(unfixed)`	unimportant	Not reported	Not reported
Debian	binutils	source	trixie	`(unfixed)`	unimportant	Not reported	Not reported
Debian	binutils	source	bookworm	`(unfixed)`	unimportant	Not reported	Not reported

OpenFactory catalog packages

[Debian 12 (Bookworm)]

[binutils]Affected
Details (2)
- 2.40-2 · amd64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
- 2.40-2 · arm64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
[binutils-aarch64-linux-gnu]Affected
Source package: [binutils]
Details (2)
- 2.40-2 · amd64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
- 2.40-2 · arm64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
[binutils-aarch64-linux-gnu-dbg]Affected
Source package: [binutils]
Details (2)
- 2.40-2 · amd64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
- 2.40-2 · arm64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
[binutils-alpha-linux-gnu]Affected
Source package: [binutils]
Details (1)
- 2.40-2 · amd64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
[binutils-alpha-linux-gnu-dbg]Affected
Source package: [binutils]
Details (1)
- 2.40-2 · amd64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
[binutils-arc-linux-gnu]Affected
Source package: [binutils]
Details (2)
- 2.40-2 · amd64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
- 2.40-2 · arm64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
[binutils-arc-linux-gnu-dbg]Affected
Source package: [binutils]
Details (2)
- 2.40-2 · amd64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
- 2.40-2 · arm64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
[binutils-arm-linux-gnueabi]Affected
Source package: [binutils]
Details (2)
- 2.40-2 · amd64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
- 2.40-2 · arm64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
[binutils-arm-linux-gnueabi-dbg]Affected
Source package: [binutils]
Details (2)
- 2.40-2 · amd64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
- 2.40-2 · arm64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
[binutils-arm-linux-gnueabihf]Affected
Source package: [binutils]
Details (2)
- 2.40-2 · amd64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
- 2.40-2 · arm64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
[binutils-arm-linux-gnueabihf-dbg]Affected
Source package: [binutils]
Details (2)
- 2.40-2 · amd64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
- 2.40-2 · arm64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
[binutils-common]Affected
Source package: [binutils]
Details (2)
- 2.40-2 · amd64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
- 2.40-2 · arm64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
[binutils-dev]Affected
Source package: [binutils]
Details (2)
- 2.40-2 · amd64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
- 2.40-2 · arm64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
[binutils-doc]Affected
Source package: [binutils]
Details (2)
- 2.40-2 · all · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
- 2.40-2 · all · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
[binutils-for-build]Affected
Source package: [binutils]
Details (2)
- 2.40-2 · all · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
- 2.40-2 · all · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
[binutils-for-host]Affected
Source package: [binutils]
Details (2)
- 2.40-2 · amd64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
- 2.40-2 · arm64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
[binutils-hppa64-linux-gnu]Affected
Source package: [binutils]
Details (1)
- 2.40-2 · amd64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
[binutils-hppa64-linux-gnu-dbg]Affected
Source package: [binutils]
Details (1)
- 2.40-2 · amd64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
[binutils-hppa-linux-gnu]Affected
Source package: [binutils]
Details (1)
- 2.40-2 · amd64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12
[binutils-hppa-linux-gnu-dbg]Affected
Source package: [binutils]
Details (1)
- 2.40-2 · amd64 · bookworm
  Affected
  nvd · binutils · debian · bookworm; nvd · binutils · debian · 12

Next results

Observed: Oct 23, 2026, 9:43:10 PM UTC

References

[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]