CVE-2026-12495

Web administration crash via login request overflow

Published Jul 27, 2026 · Updated Jul 27, 2026

Stack overflow in MERCUSYS MB115-4G 1.7.0 through 1.9.0 allows remote attackers to crash its web administration service. The http_gdpr_decrypt function mishandles attacker-controlled data from /cgi/login and writes beyond a stack buffer, corrupting memory. No authentication or user interaction is required, but adjacent-network access is required and the documented consequence is an httpd process crash.

CVSS severity5.3
Medium
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack overflow in MERCUSYS MB115-4G 1.7.0 through 1.9.0 allows remote attackers to crash its web administration service. The http_gdpr_decrypt function mishandles attacker-controlled data from /cgi/login and writes beyond a stack buffer, corrupting memory. No authentication or user interaction is required, but adjacent-network access is required and the documented consequence is an httpd process crash.

The record

CVE
CVE-2026-12495
Published
Jul 27, 2026
Updated
Jul 27, 2026
Vendor
MERCUSYS
Product
MB115-4G
Classifications
CWE-121, T1499.004
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 27, 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=1.7.0 <=1.9.0

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

MERCUSYS · MB115-4Gversion=1.7.0 <=1.9.0

Published CVSS scores

5.3INCIBECVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

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)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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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