CVE-2026-42996Public exploitNetwork attack vector

Remote application crash via unchecked grid matches

Published May 1, 2026 · Updated May 1, 2026

Stack-based buffer overflow in JS8Call through 2.3.1 and JS8Call-improved before 3.0 allows remote attackers to crash the application. The grid2deg function in APRSISClient.cpp writes regex-matched coordinate pairs into fixed 22-element stack arrays without stopping when the index exceeds their bounds. A crafted @APRSIS GRID radio transmission reaches the parser through radio or sound-card input, and APRS reporting is enabled by default; the demonstrated consequence is an application crash.

CVSS severity10.0
Critical
EPSS probability0.48%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in JS8Call through 2.3.1 and JS8Call-improved before 3.0 allows remote attackers to crash the application. The grid2deg function in APRSISClient.cpp writes regex-matched coordinate pairs into fixed 22-element stack arrays without stopping when the index exceeds their bounds. A crafted @APRSIS GRID radio transmission reaches the parser through radio or sound-card input, and APRS reporting is enabled by default; the demonstrated consequence is an application crash.

The record

CVE
CVE-2026-42996
Published
May 1, 2026
Updated
May 1, 2026
Vendor
JS8Call-improved
Product
JS8Call-improved
Classifications
CWE-121, CWE-129, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 1, 2026CVE publishedPublication date reported by the CVE source.
  2. May 1, 2026Record 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=0 <3.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

JS8Call-improved · JS8Call-improvedversion=0 <3.0
JS8Call · JS8Callversion=0 <=2.3.1

Published CVSS scores

10.0MITRECVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
7.5GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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.

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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-121Stack-based Buffer Overflow
CWE-129Improper Validation of Array Index
T1499.004Endpoint Denial of Service: Application or System Exploitation

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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