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.
CVE-2026-81878
MEDIUMPre-NVD 5.55.5—Trending — 3 sources updated this weekElevated
EchelonGraph scoreMEDIUM confidence
This medium-severity CVE scores 5.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 93% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: epss, secondary
5.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.5Exploit: Elevated riskExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 5.5
- EG Score
- 5.5(medium)
- EG Risk
- 41(Track)EG Risk 41/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity55% × 45%Exploitation40% × 40%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 7%
- KEV
- Not listed
Published
September 22, 2026
Last Modified
September 23, 2026
Advisory Details (5)
Auto-updated Sep 22, 2026🔬 Proof of concept available. Patch available. Sources: github, github_pr, github_commit, github_release.
github_release Patch Available
6.2.0
Patch available: radareorg/radare2 6.2.0
https://github.com/radareorg/radare2/releases/tag/6.2.0github_commit
commit 6727454b666b (radareorg/radare2)
Fix landed in radareorg/radare2 commit 6727454b666b — awaiting tagged release
https://github.com/radareorg/radare2/commit/6727454b666b28c33837b219a5f91136461357c0github_pr
Fix heap write overflow in Python pickle parser ##crash
Fix merged in radareorg/radare2 PR #26177 on 2026-07-06 — awaiting tagged release
https://github.com/radareorg/radare2/pull/26177generic🟡 PoC Available
[Security] Heap out-of-bounds write in PYC marshal ASCII object reader via 32-bit size overflow · Issue #26222 · radareorg/radare2 · GitHub
https://github.com/radareorg/radare2/issues/26222github Patch Available
Integer overflow causes heap out-of-bounds write in radare2 PYC parser · Advisory · radareorg/radare2 · GitHub
https://github.com/radareorg/radare2/security/advisories/GHSA-9phv-v2w8-56j3Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 9× in last 7d / 9× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-09-24 20:30 UTCEG score recompute
- 2026-09-24 14:04 UTCEPSS rescore
- 2026-09-23 18:39 UTCEG score recompute
- 2026-09-23 17:54 UTCEPSS rescore
- 2026-09-22 18:33 UTCEG score recompute
- 2026-09-22 17:58 UTCEG score recompute
- 2026-09-22 16:20 UTCEG score recompute
- 2026-09-22 15:20 UTCEG score recompute
- 2026-09-22 15:19 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-81878?
CVE-2026-81878 is a medium vulnerability published on September 22, 2026. 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…
When was CVE-2026-81878 disclosed?
CVE-2026-81878 was first published in the National Vulnerability Database on September 22, 2026, with the most recent update on September 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-81878 actively exploited?
CVE-2026-81878 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 93.1% of all scored CVEs.
What is the CVSS score of CVE-2026-81878?
CVE-2026-81878 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2026-81878?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-81878, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-81878
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