CVE-2020-28589Public exploitNetwork attack vector

Code execution via negative vertex array index

Published Aug 11, 2021 · Updated Aug 4, 2024

Improper array index validation in TinyObjLoader 2.0-rc1 and development commit 79d4421 allows attackers to execute code via a crafted OBJ file. In tiny_obj_loader.h, exportGroupsToShape accepts a negative vertex index; the caller later uses it to read attrib.vertices out of bounds. Execution requires an application embedding the library to parse attacker-controlled OBJ data, and impact occurs in that host process context.

CVSS severity9.6
Critical
EPSS probability1.88%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper array index validation in TinyObjLoader 2.0-rc1 and development commit 79d4421 allows attackers to execute code via a crafted OBJ file. In tiny_obj_loader.h, exportGroupsToShape accepts a negative vertex index; the caller later uses it to read attrib.vertices out of bounds. Execution requires an application embedding the library to parse attacker-controlled OBJ data, and impact occurs in that host process context.

The record

CVE
CVE-2020-28589
Published
Aug 11, 2021
Updated
Aug 4, 2024
Vendor
TinyObjLoader Project
Product
TinyObjLoader
Classifications
CWE-129, CAPEC-100, T1203, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 11, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=tinyobjloader development commit 79d4421 , tinyobjloader v2.0-rc1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

TinyObjLoader Project · TinyObjLoaderversion=tinyobjloader development commit 79d4421 , tinyobjloader v2.0-rc1

Published CVSS scores

6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P
9.6Cisco TalosCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-129Improper Validation of Array Index
CAPEC-100Overflow Buffers
T1203Exploitation for Client Execution
T1204.002User Execution Malicious File

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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