CVE-2026-5720

Service interruption and memory disclosure via quote underflow

Published Apr 17, 2026 · Updated Apr 17, 2026

Out-of-bounds read in MiniUPnPd before 2.3.10 allows remote attackers to disclose memory or interrupt service via a malformed SOAPAction header. In ParseHttpHeaders(), a one-byte single-quoted value passes the quote-removal test, so subtracting two from its unsigned length makes memchr() scan beyond the request buffer. Access to the HTTP/SOAP listener is required; published sources do not specify whether the resulting service interruption is a crash or hang.

CVSS severity7.1
High
EPSS probability0.67%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in MiniUPnPd before 2.3.10 allows remote attackers to disclose memory or interrupt service via a malformed SOAPAction header. In ParseHttpHeaders(), a one-byte single-quoted value passes the quote-removal test, so subtracting two from its unsigned length makes memchr() scan beyond the request buffer. Access to the HTTP/SOAP listener is required; published sources do not specify whether the resulting service interruption is a crash or hang.

The record

CVE
CVE-2026-5720
Published
Apr 17, 2026
Updated
Apr 17, 2026
Vendor
MiniUPnP Project
Product
MiniUPnPd
Classifications
CWE-191, CWE-125, T1499.004
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 17, 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 <2.3.10

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

MiniUPnP Project · MiniUPnPdversion=0 <2.3.10

Published CVSS scores

7.1VulnCheckCVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N
9.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/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.

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

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-191Integer Underflow (Wrap or Wraparound)
CWE-125Out-of-bounds Read
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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