SUSE CVE-2026-18220

🗓️ 07 Aug 2026 23:57:08Reported by Suse CVEType

Out-of-bounds write in the DLX ELF backend of binutils enables code execution via file stream programming when the DLX backend is enabled.

Reporter	Title	Published	Views	Family All 14
ATTACKERKB	CVE-2026-18220	29 Jul 202609:47	–	attackerkb
Circl	CVE-2026-18220	29 Jul 202615:00	–	circl
CVE	CVE-2026-18220	29 Jul 202609:47	–	cve
Cvelist	CVE-2026-18220 Binutils: binutils: out-of-bounds write in bfd dlx elf backend relocation processing	29 Jul 202609:47	–	cvelist
Debian CVE	CVE-2026-18220	29 Jul 202609:47	–	debiancve
EUVD	EUVD-2026-50279	29 Jul 202609:47	–	euvd
NVD	CVE-2026-18220	29 Jul 202611:16	–	nvd
OSV	DEBIAN-CVE-2026-18220	29 Jul 202611:16	–	osv
OSV	ECHO-2327-9760-E268 Claimed out-of-bounds write in dlx_rtype_to_howto() (bfd/elf32-dlx.c), reached from elf32_dlx_info_to_howto_rel() via the relocation type of a crafted ELF/DLX object. The DLX backend is not built. dlx_elf32_be_vec is selected only by the dlx-*-elf target triple (bfd/config.bfd), and that vec is the sole trigger for compiling elf32-dlx.lo (bfd/configure.ac); debian/rules passes an explicit per-architecture --enable-targets list and never --enable-targets=all. Verified against the shipped amd64 and arm64 debs: libbfd exports no dlx symbols, `objdump -b elf32-dlx` returns "invalid bfd target", `ld -m elf32dlx` is an unrecognised emulation, and a crafted EM_DLX (0x5aa5) object carrying relocation types past the end of the howto table is claimed by the generic elf32-big backend, which reports "architecture: UNKNOWN!" and every relocation as UNKNOWN. The function is never entered. Note that readelf prints DLX machine and relocation names from its own tables, independent of BFD, so its output is not evidence of the backend being present. Upstream also rejects the finding on its merits, even with DLX enabled. On the Red Hat bug that Debian's tracker carries as its only reference, maintainer Andrew Burgess concludes "I don't believe that this is actually a bug": DLX relocation types are a contiguous 0-9, not the non-contiguous space with extended types at 0x10000+ that the advisory describes; dlx_rtype_to_howto() already rejects r_type >= R_DLX_max (10); and types 6-9 have their own case arms, so the indexed access can only ever reach 0-5 of the 6-entry dlx_elf_howto_table. Patrick Monnerat adds that the advisory claims an out-of-bounds write while the procedure performs no indexed write at all. Both observations hold against the 2.45.50.20251201 source. Debian marks it unimportant (binutils not covered by security support) and ships no fix in any suite including forky/sid, so there is nothing to bump.	30 Jul 202607:51	–	osv
OSV	UBUNTU-CVE-2026-18220	29 Jul 202611:16	–	osv