How severe is CVE-2016-8622?

CVE-2016-8622 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-2016-8622 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-2016-8622?

CVE-2016-8622 affects Haxx Libcurl. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2016-8622?

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

When was CVE-2016-8622 published?

CVE-2016-8622 was published on 2018-07-31 and last updated on 2026-06-17.

CVE-2016-8622

CVE-2016-8622 is a low-severity vulnerability in Haxx Libcurl 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-787.

Key facts

Severity: Low (CVSS 3.x base score 3.7)
CVSS v2: 7.5
EPSS exploit prediction: 5% (91st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Haxx Libcurl
Published: 2018-07-31
Last modified: 2026-06-17

Description

The URL percent-encoding decode function in libcurl before 7.51.0 is called `curl_easy_unescape`. Internally, even if this function would be made to allocate a unscape destination buffer larger than 2GB, it would return that new length in a signed 32 bit integer variable, thus the length would get either just truncated or both truncated and turned negative. That could then lead to libcurl writing outside of its heap based buffer.

Frequently asked questions

What is CVE-2016-8622?: The URL percent-encoding decode function in libcurl before 7.51.0 is called `curl_easy_unescape`. Internally, even if this function would be made to allocate a unscape destination buffer larger than 2GB, it would return that new length in a signed 32 bit integer variable, thus the length would get either just truncated or both truncated and turned negative. That could then lead to libcurl writing outside of its heap based buffer.
How severe is CVE-2016-8622?: CVE-2016-8622 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-2016-8622 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-2016-8622?: CVE-2016-8622 affects Haxx Libcurl. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2016-8622?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2016-8622 published?: CVE-2016-8622 was published on 2018-07-31 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:haxx:libcurl:*:*:*:*:*:*:*:*

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