CVE-2026-81879 radare2: Heap out-of-bounds read in radare2 ELF PN_XNUM handling
Attackers can cause denial of service in radare2 by processing a crafted ELF file that triggers a heap out-of-bounds read.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-81879?
CVE-2026-81879 is a medium-severity memory corruption vulnerability in Radare Radare2, published on 22 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
radare2 is a UNIX-like reverse engineering framework and command-line toolset. Prior to 6.2.0, radare2's ELF PN_XNUM handling was vulnerable because the ELF parser allocated the program-header array using the resolved PN_XNUM count but several consumers still iterated with the original e_phnum value of 65535. The vulnerability is triggered by processing a crafted ELF file with e_phnum = 0xffff and a much smaller resolved count in shdr[0].sh_info. Consumers iterated beyond the allocated program-header array. This can cause a heap out-of-bounds read and process termination, resulting in denial of service; memory disclosure and code execution have not been demonstrated. This issue is fixed in version 6.2.0.
Weakness: CWE-125
Which versions are affected by CVE-2026-81879?
It affects 1 product.
Products include Radare Radare2.
How do I fix CVE-2026-81879?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-81879 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-81879 exists.
Other vulnerabilities in Radare Radare2
Sources
Also known as GHSA-jqfq-hvcp-xh4p, UBUNTU-CVE-2026-81879.