CVE-2026-81878

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

Published Sep 22, 2026 CVSS 3.1 · 5.5 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Radare
Radare radare2
CPEs cpe:2.3:a:radare:radare2:*:*:*:*:*:*:*:*
Vendors & Products Radare
Radare radare2
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Radareorg
Radareorg radare2
Vendors & Products Radareorg
Radareorg radare2
Type Values Removed Values Added
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.
Title radare2: Integer overflow causes heap out-of-bounds write in radare2 PYC parser
Weaknesses CWE-190
CWE-787
References
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 22, 2026, 5:55 PM
Reserved
Aug 27, 2026, 5:48 PM
Status
Analyzed
Published
Sep 22, 2026, 4:18 PM
Modified
Sep 25, 2026, 4:54 PM