How severe is CVE-2016-8616?

CVE-2016-8616 has a CVSS 3.x base score of 3.7, rated low severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2016-8616 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (88th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-8616?

CVE-2016-8616 affects Haxx Curl. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2016-8616?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2016-8616 published?

CVE-2016-8616 was published on 2018-08-01 and last updated on 2026-06-17.

CVE-2016-8616

CVE-2016-8616 is a low-severity vulnerability in Haxx Curl with a CVSS 3.x base score of 3.7. 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-255.

Key facts

Severity: Low (CVSS 3.x base score 3.7)
CVSS v2: 4.3
EPSS exploit prediction: 3% (88th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-255
Affected product: Haxx Curl
Published: 2018-08-01
Last modified: 2026-06-17

Description

A flaw was found in curl before version 7.51.0 When re-using a connection, curl was doing case insensitive comparisons of user name and password with the existing connections. This means that if an unused connection with proper credentials exists for a protocol that has connection-scoped credentials, an attacker can cause that connection to be reused if s/he knows the case-insensitive version of the correct password.

Frequently asked questions

What is CVE-2016-8616?: A flaw was found in curl before version 7.51.0 When re-using a connection, curl was doing case insensitive comparisons of user name and password with the existing connections. This means that if an unused connection with proper credentials exists for a protocol that has connection-scoped credentials, an attacker can cause that connection to be reused if s/he knows the case-insensitive version of the correct password.
How severe is CVE-2016-8616?: CVE-2016-8616 has a CVSS 3.x base score of 3.7, rated low severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2016-8616 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (88th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-8616?: CVE-2016-8616 affects Haxx Curl. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2016-8616?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2016-8616 published?: CVE-2016-8616 was published on 2018-08-01 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*

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