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Squid CVE-2026-47729

| EUVDEUVD-2026-44962 MEDIUM
Out-of-bounds Read (CWE-125)
2026-06-12
Buffer Overflow Information Disclosure Squid Squid Cache
6.5
CVSS 3.1 · Vendor
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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Access Squid network service
  2. Exploit
    Trigger unknown vulnerability
  3. Impact
    Achieve unknown impact

Vulnerability Assessment

Weakness
CWE
CWE-125
ASVS 5.0
V15 - Secure Coding and Architecture Bounds checking, read limits
MITRE ATT&CK

1 technique across 1 tactic: Collection

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

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Exploitation Conditions

Exploitation conditions are UNKNOWN. The oss-security disclosure does not include technical details, configuration prerequisites, or triggering conditions in the data provided. No CVSS vector is available to infer attack vector or privilege requirements. No special conditions can be confirmed or denied. Security teams should not assume either a best-case (authenticated, complex) or worst-case (unauthenticated, trivial) scenario until the full disclosure is published.
Impact

Risk cannot be meaningfully assessed at this time due to an absence of all quantitative and qualitative signals. No CVSS base score or vector is available, preventing evaluation of attack vector, complexity, privileges required, or impact scope. No EPSS score exists (pre-NVD). The vulnerability is NOT listed in CISA KEV. No POC code has been identified. The only positive signal is that Squid is a network-facing service deployed at scale, meaning any remotely exploitable vulnerability in it historically carries significant real-world risk. However, this is a class-level inference about Squid generally - NOT a confirmed characteristic of this specific CVE. EXPLICIT DATA GAP: Attack vector (network vs. local), authentication requirements, and impact category (confidentiality, integrity, availability) are ALL unknown and must not be assumed.
Exploit ScenarioDerived

An exploit scenario cannot be responsibly constructed from available data. No technical description of the vulnerability mechanism has been published. Squid's typical exposure as a network-accessible proxy means that if the vulnerability is remotely exploitable without authentication (which is unconfirmed), an attacker with network access to the proxy port would be the realistic threat actor - but this is speculative and must not be treated as confirmed.
This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).
Patch available 1.9% exploitation probability (EPSS)

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AnalysisAIv1 – Jun 12, 2026

Squid proxy server is affected by CVE-2026-47729, disclosed alongside CVE-2026-50012 in a single oss-security post dated 2026-06-12 by Amos Jeffries. This is a pre-NVD disclosure, meaning technical details, affected versions, CVSS scores, and patch information have not yet been published to the NVD. No exploit code has been identified at time of analysis, and CISA KEV status is not confirmed.

RemediationAI

No patch version or vendor advisory with remediation guidance is available from the provided data. Organizations running Squid should monitor the oss-security thread at https://www.openwall.com/lists/oss-security/2026/06/12 and the official Squid security advisory page (https://www.squid-cache.org/Advisories/) for patch releases. As a general compensating control pending patch availability, operators should restrict external access to the Squid listener port to trusted source IP ranges only, and ensure Squid is not exposed directly to untrusted networks - however, the effectiveness of these mitigations depends on the actual attack vector, which is currently unknown. Patch status is: No vendor-released patch identified at time of analysis.

Affected VersionsENISA

squid < 7.6

Affected Packages

euvd squid fix: 7.6

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

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Technical ContextAI · show details

Squid is a widely deployed open-source caching and forwarding HTTP/HTTPS proxy used in enterprise and ISP environments. It supports a broad range of protocols including HTTP, HTTPS, FTP, and TLS interception. The specific vulnerability class (CWE) for CVE-2026-47729 is NOT available in the provided data - no CWE, CPE, or technical description has been published. The co-disclosure with CVE-2026-50012 in a single oss-security thread by the same author (Amos Jeffries, a known Squid maintainer) suggests both issues may have been discovered or patched concurrently, but the relationship between them cannot be confirmed from available data.

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  • Exploit and PoC references, threat intelligence from 22 sources
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Severity by source

Vendor (CNA) PRIMARY 6.5 MEDIUM
AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
SUSE MEDIUM
Red Hat 6.5 MEDIUM

Primary rating from Vendor (CNA).

CVSS VectorVendor

Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

Lifecycle Timeline

2
Patch available
Jul 16, 2026 - 18:18 EUVD
CVSS changed
Jul 16, 2026 - 17:22 NVD
6.5 (MEDIUM)

Description PRE-NVD

Disclosed via oss-security. NVD scoring and full description are pending.

Threat Intelligence Overview

EPSS Score
1.9%
Top 23% exploitable
Exploit
POC
Public exploit code exists
Social Media
1
Sightings
Data Quality
7 sources
Confidence: High
EUVD NVD CVE.org EPSS MSRC Vendor CIRCL GitHub VulDB

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity MEDIUM
CISA KEV No
Public POC Yes
EPSS 1.9%
Patch available Yes
Active threat No
Deciding rule
MEDIUM severity (CVSS 4.0-6.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Scheduled
Exploitation· derived
Poc
System Exposure· derived
Open
Automatable· derived
No
Human Impact· derived
Medium

Priority Score

54
Low Medium High Critical
KEV: 0
EPSS: +2
CVSS: +32
PoC: +20
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Buffer Overflow HIGH

A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.

Information Disclosure MEDIUM

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.

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Same weakness CWE-125 – Out-of-bounds Read

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Same technique Buffer Overflow

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CVE-2019-11043 CRITICAL POC
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CVE-2009-0927 HIGH POC
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CVE-2012-1889 HIGH POC
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Vendor StatusVendor

SUSE

Severity: Moderate
Product Status
SUSE Linux Enterprise High Performance Computing 15 SP7 Affected
SUSE Linux Enterprise Module for Server Applications 15 SP7 Affected
SUSE Linux Enterprise Server 15 SP7 Affected
SUSE Linux Enterprise Server 16.0 Affected
SUSE Linux Enterprise Server 16.1 Affected

References

Advisories & patches
ADVISORY https://seclists.org/oss-sec/2026/q2/1013 ADVISORY https://seclists.org/oss-sec/2026/q2/1016 ADVISORY https://seclists.org/oss-sec/2026/q2/896 ADVISORY https://seclists.org/oss-sec/2026/q2/930 ADVISORY https://seclists.org/oss-sec/2026/q2/969 ADVISORY https://seclists.org/oss-sec/2026/q2/995 ADVISORY https://ubuntu.com/security/notices/USN-8941-1 ADVISORY https://vuldb.com/vuln/370669 ADVISORY https://www.openwall.com/lists/oss-security/2026/06/12 REF https://github.com/squid-cache/squid/commit/865a131c7d557e68c965043d98c2eccae26deef8 REF https://github.com/squid-cache/squid/pull/2408 REF https://github.com/squid-cache/squid/pull/2409 REF https://github.com/squid-cache/squid/releases/tag/SQUID_7_6 REF https://github.com/squid-cache/squid/security/advisories/GHSA-8c37-pxjq-qwrg

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