Buffer overflow in Radare Radare2
CVE-2026-81878
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.
Vulnerability class: Integer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.002 (10.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 10th percentile — 10.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000
Affected products
- Radare Radare2
- Radareorg Radare2 — versions < 6.2.0
Weakness classification (CWE)
References
- github.com/radareorg/radare2/security/advisories/GHSA-9phv-v2w8-56j3 (Patch, Vendor Advisory)
- github.com/radareorg/radare2/issues/26222 (Exploit, Mitigation, Vendor Advisory)
- github.com/radareorg/radare2/pull/26177 (Patch)
- github.com/radareorg/radare2/commit/6727454b666b28c33837b219a5f91136461357c0 (Patch)
- github.com/radareorg/radare2/releases/tag/6.2.0 (Release Notes)
Frequently asked questions
- What is CVE-2026-81878?
- CVE-2026-81878 is a medium-severity vulnerability in Radare Radare2, classified under Integer Overflow or Wraparound. CVSS score: 5.5/10. Published 2026-09-22.
- How severe is CVE-2026-81878?
- Medium severity. CVSS v3 base score is 5.5 out of 10.