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Vulnerability · Published Sep 22, 2026 · Assigned by GitHub_M

CVE-2026-81879radare2: Heap out-of-bounds read in radare2 ELF PN_XNUM handling

Medium 5.5

In plain English

A medium-severity out-of-bounds read in radare2 from radareorg. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities).

Severity (CVSS 3.1)5.5Medium
Exploit odds (30 days)0.2%top 92.1% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Ubuntu:26.04:LTSradare2no fix listedUBUNTU-CVE-2026-81879
Ubuntu:26.10radare2no fix listedUBUNTU-CVE-2026-81879

Affected products (as reported)

VendorProductVersions
radareorg radare2 < 6.2.0

Weakness: CWE-125 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

References