Squid 3.x before 3.5.16 and 4.x before 4.0.8 improperly perform bounds checking, which allows remote attackers to cause a denial of service via a crafted HTTP response, related to Vary headers.
CVE-2016-3948
Score elevated to 7.6 because EPSS predicts 35% probability of exploitation within the next 30 days (top 1.7% of all CVEs). NVD baseline CVSS 7.5 retained for reference. Confidence: see factors.
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 7.5
- EG Score
- 7.6(high)
- EG Risk
- 55(Track)EG Risk 55/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity76% × 45%Exploitation40% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 35%
- EPSS %ILE
- 98%
- KEV
- Not listed
Published
April 7, 2016
Last Modified
June 17, 2026
References (18)
- cve@mitrehttp://lists.opensuse.org/opensuse-security-announce/2016-08/msg00010.html
- cve@mitrehttp://lists.opensuse.org/opensuse-security-announce/2016-08/msg00040.html
- cve@mitrehttp://lists.opensuse.org/opensuse-updates/2016-08/msg00069.html
- cve@mitrehttp://rhn.redhat.com/errata/RHSA-2016-2600.html
- cve@mitrehttp://www.securitytracker.com/id/1035458
- cve@mitrehttp://www.squid-cache.org/Advisories/SQUID-2016_4.txt
- cve@mitrehttp://www.squid-cache.org/Versions/v3/3.5/changesets/squid-3.5-14016.patch
- cve@mitrehttps://security.gentoo.org/glsa/201607-01
- cve@mitrehttps://usn.ubuntu.com/3557-1/
- af854a3a-2127-422b-91ae-364da2661108http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00010.html
- af854a3a-2127-422b-91ae-364da2661108http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00040.html
- af854a3a-2127-422b-91ae-364da2661108http://lists.opensuse.org/opensuse-updates/2016-08/msg00069.html
- af854a3a-2127-422b-91ae-364da2661108http://rhn.redhat.com/errata/RHSA-2016-2600.html
- af854a3a-2127-422b-91ae-364da2661108http://www.securitytracker.com/id/1035458
- af854a3a-2127-422b-91ae-364da2661108http://www.squid-cache.org/Advisories/SQUID-2016_4.txt
Patch Availability(2)
| Vendor / Ecosystem | Fixed in / Patch | Released | Source |
|---|---|---|---|
| ubuntu | squidclient (3.3.8-1ubuntu6.11) @ trusty | 2026-05-22 | ubuntu |
| redhat | squid-7:3.5.20-2.el7 | 2016-11-03 | redhat |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Affected Packages
(5 across 5 ecosystems)
Debian:11(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| squid | — | 4.1-1 | — |
Debian:12(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| squid | — | 4.1-1 | — |
Debian:13(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| squid | — | 4.1-1 | — |
Debian:14(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| squid | — | 4.1-1 | — |
Debian:8(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| squid3 | 3.4.8-6, 3.4.8-6+deb8u1, 3.4.8-6+deb8u2, 3.4.8-6+deb8u2~bpo70+1 | 3.4.8-6+deb8u3 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
All Vendor Advisories
(2)
Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.
Data Freshness Timeline
(refreshed 5× in last 7d / 21× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-08-19 16:59 UTCEPSS rescore
- 2026-08-18 13:43 UTCEPSS rescore
- 2026-08-16 14:51 UTCEPSS rescore
- 2026-08-16 02:09 UTCEPSS rescore
- 2026-08-15 01:25 UTCEPSS rescore
- 2026-08-14 12:54 UTCOSV refresh
- 2026-08-12 13:46 UTCEPSS rescore
- 2026-08-11 13:36 UTCEPSS rescore
- 2026-08-08 16:32 UTCEPSS rescore
- 2026-08-06 13:42 UTCEPSS rescore
- 2026-08-05 19:12 UTCEPSS rescore
- 2026-08-04 15:04 UTCEPSS rescore
- 2026-08-04 10:32 UTCEPSS rescore
- 2026-08-01 04:11 UTCEPSS rescore
- 2026-07-30 16:23 UTCEPSS rescore
- 2026-07-30 01:54 UTCOSV refresh
- 2026-07-28 15:31 UTCEPSS rescore
- 2026-07-26 14:50 UTCEPSS rescore
- 2026-07-25 14:13 UTCEPSS rescore
- 2026-07-23 14:14 UTCEPSS rescore
- 2026-07-23 01:23 UTCEG score recompute▲ 0.10
- 2026-07-22 22:02 UTCEG score recompute
- 2026-07-22 14:04 UTCEPSS rescore
- 2026-07-21 15:21 UTCEPSS rescore
- 2026-07-21 15:21 UTCEPSS rescore
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- 2026-07-20 17:03 UTCEPSS rescore
- 2026-07-19 14:27 UTCEPSS rescore
- 2026-07-19 02:26 UTCEPSS rescore
- 2026-07-19 02:26 UTCEPSS rescore
- 2026-07-16 16:59 UTCEPSS rescore
- 2026-07-16 16:59 UTCEPSS rescore
- 2026-07-15 16:54 UTCEPSS rescore
- 2026-07-15 16:54 UTCEPSS rescore
- 2026-07-15 01:56 UTCEPSS rescore
- 2026-07-15 01:56 UTCEPSS rescore
- 2026-07-13 22:26 UTCEPSS rescore
- 2026-07-13 06:09 UTCEPSS rescore
- 2026-07-12 11:07 UTCOSV refresh
- 2026-07-12 05:43 UTCEPSS rescore
- 2026-07-12 05:43 UTCEPSS rescore
- 2026-07-11 08:23 UTCEPSS rescore
- 2026-07-09 19:05 UTCEPSS rescore
- 2026-07-07 13:42 UTCEPSS rescore
- 2026-07-04 06:28 UTCEPSS rescore
- 2026-07-01 15:02 UTCEPSS rescore
- 2026-06-30 23:19 UTCEPSS rescore
- 2026-06-29 14:03 UTCEPSS rescore
- 2026-06-28 04:53 UTCEPSS rescore
- 2026-06-25 13:47 UTCEPSS rescore
- 2026-06-25 13:47 UTCEPSS rescore
- 2026-06-24 14:02 UTCEPSS rescore
- 2026-06-24 14:02 UTCEPSS rescore
- 2026-06-23 21:30 UTCEPSS rescore
- 2026-06-23 16:30 UTCOSV refresh
- 2026-06-21 01:57 UTCEPSS rescore
- 2026-06-21 01:57 UTCEPSS rescore
- 2026-06-18 17:50 UTCEPSS rescore
- 2026-06-17 17:50 UTCEPSS rescore
- 2026-06-17 17:50 UTCEPSS rescore
- 2026-06-16 17:50 UTCEPSS rescore
- 2026-06-16 17:50 UTCEPSS rescore
- 2026-06-15 17:45 UTCEPSS rescore
- 2026-06-14 23:14 UTCEPSS rescore
- 2026-06-13 22:57 UTCEPSS rescore
- 2026-06-13 22:57 UTCEPSS rescore
- 2026-06-12 23:09 UTCEPSS rescore
- 2026-06-12 23:09 UTCEPSS rescore
- 2026-06-11 13:57 UTCEPSS rescore
- 2026-06-10 22:15 UTCEPSS rescore
- 2026-06-06 21:59 UTCOSV refresh
- 2026-06-05 22:44 UTCEPSS rescore
- 2026-06-05 06:08 UTCEPSS rescore
- 2026-06-05 06:08 UTCEPSS rescore
- 2026-06-04 13:10 UTCEPSS rescore
- 2026-06-04 13:10 UTCEPSS rescore
- 2026-06-02 20:10 UTCEPSS rescore
- 2026-06-01 13:49 UTCEPSS rescore
- 2026-06-01 13:49 UTCEPSS rescore
- 2026-05-31 22:28 UTCEPSS rescore
- 2026-05-31 22:28 UTCEPSS rescore
- 2026-05-31 00:14 UTCEPSS rescore
- 2026-05-29 13:41 UTCEPSS rescore
- 2026-05-27 13:38 UTCEPSS rescore
- 2026-05-27 13:38 UTCEPSS rescore
- 2026-05-26 13:42 UTCEPSS rescore
- 2026-05-22 21:15 UTCEPSS rescore
- 2026-05-22 21:15 UTCEPSS rescore
- 2026-05-22 21:00 UTCEG score recompute
- 2026-05-22 21:00 UTCVendor advisory
- 2026-05-22 21:00 UTCGHSA enrichment
- 2026-05-21 22:40 UTCEPSS rescore
- 2026-05-20 22:37 UTCEPSS rescore
- 2026-05-20 22:37 UTCEPSS rescore
- 2026-05-20 22:37 UTCEPSS rescore
- 2026-05-20 11:21 UTCEPSS rescore
- 2026-05-20 11:21 UTCEPSS rescore
- 2026-05-20 11:21 UTCEPSS rescore
- 2026-05-19 14:03 UTCOSV refresh
- 2026-05-18 21:30 UTCEPSS rescore
- 2026-05-18 21:30 UTCEPSS rescore
Related CVEs(same vendor + same CWE)
Same vendor
10 shownredhat
- CVE-2001-0825EG 10.0HIGH
- CVE-2001-1009EG 10.0EPSS p93HIGH
- CVE-2001-0554EG 10.0EPSS p98HIGH
- CVE-2001-1162EG 10.0EPSS p96HIGH
- CVE-2001-0414EG 10.0EPSS p100HIGH
- CVE-2001-0191EG 10.0EPSS p92HIGH
- CVE-2001-0301EG 10.0EPSS p91HIGH
- CVE-2001-0197EG 10.0EPSS p96HIGH
- CVE-2001-0233EG 10.0EPSS p96HIGH
- CVE-2001-0010EG 10.0EPSS p98HIGH
Same CWE
10 shownCWE-119
- CVE-2003-0819EG 10.0EPSS p99HIGH
- CVE-2003-0903EG 10.0EPSS p98HIGH
- CVE-2003-1339EG 10.0EPSS p99HIGH
- CVE-2003-0095EG 10.0EPSS p96HIGH
- CVE-2002-2227EG 10.0HIGH
- CVE-2002-2248EG 10.0EPSS p93HIGH
- CVE-2002-2250EG 10.0EPSS p94HIGH
- CVE-2002-2251EG 10.0EPSS p93HIGH
- CVE-2002-2253EG 10.0EPSS p93HIGH
- CVE-2002-2257EG 10.0EPSS p92HIGH
Frequently asked(5)
What is CVE-2016-3948?
When was CVE-2016-3948 disclosed?
Is CVE-2016-3948 actively exploited?
What is the CVSS score of CVE-2016-3948?
How do I remediate CVE-2016-3948?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2016-3948
Is Your Infrastructure Affected by CVE-2016-3948?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.