How severe is CVE-2016-3957?

CVE-2016-3957 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2016-3957 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-2016-3957?

CVE-2016-3957 affects Web2py. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2016-3957?

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

When was CVE-2016-3957 published?

CVE-2016-3957 was published on 2018-02-06 and last updated on 2026-06-17.

CVE-2016-3957

CVE-2016-3957 is a critical-severity vulnerability in Web2py with a CVSS 3.x base score of 9.8. 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-502.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 5% (91st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-502
Affected product: Web2py
Published: 2018-02-06
Last modified: 2026-06-17

Description

The secure_load function in gluon/utils.py in web2py before 2.14.2 uses pickle.loads to deserialize session information stored in cookies, which might allow remote attackers to execute arbitrary code by leveraging knowledge of encryption_key.

Frequently asked questions

What is CVE-2016-3957?: The secure_load function in gluon/utils.py in web2py before 2.14.2 uses pickle.loads to deserialize session information stored in cookies, which might allow remote attackers to execute arbitrary code by leveraging knowledge of encryption_key.
How severe is CVE-2016-3957?: CVE-2016-3957 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2016-3957 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-2016-3957?: CVE-2016-3957 affects Web2py. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2016-3957?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2016-3957 published?: CVE-2016-3957 was published on 2018-02-06 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:web2py:web2py:*:*:*:*:*:*:*:*

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