CVE-2026-110659 in ELFIO
Summary
by MITRE • 10/14/2026
ELFIO through 3.12 contains a NULL pointer dereference vulnerability in relocation_section_accessor get_entry() that allows attackers to crash applications via an unvalidated sh_link index. Attackers can supply a crafted ELF file whose SHT_REL or SHT_RELA section has a dangling sh_link, causing find_hash_section() to dereference null and deny service.
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Analysis
by VulDB Data Team • 10/14/2026
The vulnerability identified in the ELFI0 library through version 3.12 represents a critical flaw within its relocation processing logic, specifically located in the get_entry method of the relocation_section_accessor class. This component is responsible for parsing ELF binary files to extract relocation information necessary for linking and loading executables or shared libraries. The core technical issue stems from an insufficient validation of the sh_link field found within SHT_REL or SHT_RELA section headers. In a valid ELF structure, this index points to another section header that contains symbol table entries required to resolve relocations. However, when processing malformed input where this index is invalid or references non-existent sections, the library fails to verify its validity before proceeding with subsequent operations.
This lack of validation directly leads to a NULL pointer dereference during the execution of find_hash_section(). When the sh_link value points outside the bounds of valid section headers or refers to an empty slot in the section header table, the internal lookup mechanism returns a null pointer instead of handling the error gracefully. The application then attempts to dereference this null pointer to access properties of the target section, resulting in an immediate segmentation fault and process termination. This behavior effectively transforms a parsing routine into a denial-of-service vector against any software that utilizes ELFI0 to load untrusted or maliciously crafted ELF binaries.
From a security classification perspective, this flaw aligns with CWE-476, which denotes NULL Pointer Dereference vulnerabilities where an application dereferences a pointer it expects to be valid but is actually null. The operational impact is primarily focused on availability rather than confidentiality or integrity in the immediate sense, as the primary outcome is the crash of the host application. This places the vulnerability within the ATT&CK framework under techniques related to Denial of Service, specifically those involving resource exhaustion via crashes caused by malformed input processing. Attackers can exploit this by distributing crafted ELF files that trigger the specific code path leading to the null dereference, thereby disrupting services or applications dependent on dynamic binary analysis or loading capabilities.
Mitigation strategies for this vulnerability involve updating ELFI0 to a version later than 3.12 where the issue has been addressed through rigorous input validation and bounds checking of section header indices. For systems unable to update immediately, defensive programming practices should be implemented by wrapping calls to relocation parsing functions in exception handlers or error-checking logic that validates return values before use. Additionally, applications processing untrusted ELF binaries should employ sandboxing techniques such as seccomp-bpf filters on Linux to restrict system call access upon crash conditions, although this is a compensatory measure rather than a fix for the underlying code defect. Ensuring strict adherence to ELF specification constraints during parsing and implementing comprehensive unit tests with malformed inputs are essential steps in preventing similar vulnerabilities in future development cycles.