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Vulnerability · Published Sep 22, 2026 · Assigned by GitHub_M

CVE-2026-81878radare2: Integer overflow causes heap out-of-bounds write in radare2 PYC parser

Medium 5.5

In plain English

A medium-severity integer overflow 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 10% of all known vulnerabilities).

Severity (CVSS 3.1)5.5Medium
Exploit odds (30 days)0.2%top 89.7% 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 CPython bytecode .pyc marshal parser was vulnerable because the CPython marshal readers accepted a 32-bit string length without rejecting values that overflow the size-plus-one allocation. The vulnerability is triggered by opening or inspecting a crafted .pyc file through r2 or rabin2. A length of 0xffffffff wrapped the allocation to zero before the common byte reader wrote attacker-controlled data and fill bytes beyond the heap allocation. This can cause heap memory corruption and denial of service; arbitrary code execution is possible but has 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-2026-81878
Ubuntu:26.10radare2no fix listedUBUNTU-CVE-2026-81878

Affected products (as reported)

VendorProductVersions
radareorg radare2 < 6.2.0

Weakness: CWE-190, CWE-787 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

References