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CVE-2019-12523

An issue was discovered in Squid before 4.9. When handling a URN request, a corresponding HTTP request is made. This HTTP request doesn't…

Critical9.1EPSS 4.3%
Published
Updated
Reserved
Assigned by
mitre

Description

An issue was discovered in Squid before 4.9. When handling a URN request, a corresponding HTTP request is made. This HTTP request doesn't go through the access checks that incoming HTTP requests go through. This causes all access checks to be bypassed and allows access to restricted HTTP servers, e.g., an attacker can connect to HTTP servers that only listen on localhost.

Timeline

  1. ID reserved

    By mitre

  2. · 6 months later

    Published

  3. · 5 years later

    Record updated

Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.

Scores

CVSS scores of CVE-2019-12523, by who scored it
Scored byCVSSScoreVector
NVDNVD · Modified3.1Critical9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS (exploitation in 30 days)
4.3% · top 8.8% of all CVEs (7 Nov 2026)
Loading the EPSS history…

The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.1.

Weakness

  • n/a

Affected products

  • n/a

    • affected n/a

References (9)

Sources

The same CVE in the primary databases and aggregators, to check against.

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Record last updated .