How severe is CVE-2016-10003?

CVE-2016-10003 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2016-10003 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-10003?

CVE-2016-10003 affects Squid-cache Squid. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2016-10003?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2016-10003 published?

CVE-2016-10003 was published on 2017-01-27 and last updated on 2026-06-17.

CVE-2016-10003

CVE-2016-10003 is a high-severity vulnerability in Squid-cache Squid with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-697.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 5% (91st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-697
Affected product: Squid-cache Squid
Published: 2017-01-27
Last modified: 2026-06-17

Description

Incorrect HTTP Request header comparison in Squid HTTP Proxy 3.5.0.1 through 3.5.22, and 4.0.1 through 4.0.16 results in Collapsed Forwarding feature mistakenly identifying some private responses as being suitable for delivery to multiple clients.

Frequently asked questions

What is CVE-2016-10003?: Incorrect HTTP Request header comparison in Squid HTTP Proxy 3.5.0.1 through 3.5.22, and 4.0.1 through 4.0.16 results in Collapsed Forwarding feature mistakenly identifying some private responses as being suitable for delivery to multiple clients.
How severe is CVE-2016-10003?: CVE-2016-10003 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2016-10003 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-10003?: CVE-2016-10003 affects Squid-cache Squid. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2016-10003?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2016-10003 published?: CVE-2016-10003 was published on 2017-01-27 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:*

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Threat intelligence

Threat-intel indicators referencing this CVE:

200.89.159.59 (ipv4-addr)
192.3.127.40 (ipv4-addr)