How severe is CVE-2017-18365?

CVE-2017-18365 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-2017-18365 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 21% (97th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2017-18365?

CVE-2017-18365 primarily affects Github. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2017-18365?

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-2017-18365 published?

CVE-2017-18365 was published on 2019-03-28 and last updated on 2026-06-17.

CVE-2017-18365

CVE-2017-18365 is a critical-severity vulnerability in Github with a CVSS 3.x base score of 9.8. Its EPSS exploit-prediction score of 21% places it in the 97th percentile, indicating an elevated likelihood of exploitation. 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: 21% (97th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-502
Affected product: Github
Published: 2019-03-28
Last modified: 2026-06-17

Description

The Management Console in GitHub Enterprise 2.8.x before 2.8.7 has a deserialization issue that allows unauthenticated remote attackers to execute arbitrary code. This occurs because the enterprise session secret is always the same, and can be found in the product's source code. By sending a crafted cookie signed with this secret, one can call Marshal.load with arbitrary data, which is a problem because the Marshal data format allows Ruby objects.

Frequently asked questions

What is CVE-2017-18365?: The Management Console in GitHub Enterprise 2.8.x before 2.8.7 has a deserialization issue that allows unauthenticated remote attackers to execute arbitrary code. This occurs because the enterprise session secret is always the same, and can be found in the product's source code. By sending a crafted cookie signed with this secret, one can call Marshal.load with arbitrary data, which is a problem because the Marshal data format allows Ruby objects.
How severe is CVE-2017-18365?: CVE-2017-18365 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-2017-18365 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 21% (97th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-18365?: CVE-2017-18365 primarily affects Github. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2017-18365?: 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-2017-18365 published?: CVE-2017-18365 was published on 2019-03-28 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:github:github:*:*:*:*:enterprise:*:*:*
cpe:2.3:a:github:github:2.8.7:*:*:*:*:*:*:*

More vulnerabilities in Github

CVE-2020-10516 — Critical (CVSS 9.8): An improper access control vulnerability was identified in the GitHub Enterprise Server API that allowed an…
CVE-2020-10519 — High (CVSS 8.8): A remote code execution vulnerability was identified in GitHub Enterprise Server that could be exploited when building…
CVE-2020-10518 — High (CVSS 8.8): A remote code execution vulnerability was identified in GitHub Enterprise Server that could be exploited when building…
CVE-2021-22863 — High (CVSS 8.1): An improper access control vulnerability was identified in the GitHub Enterprise Server GraphQL API that allowed…
CVE-2012-2055 — High (CVSS 7.5): GitHub Enterprise before 20120304 does not properly restrict the use of a hash to provide values for a model's…
CVE-2021-22862 — Medium (CVSS 6.5): An improper access control vulnerability was identified in GitHub Enterprise Server that allowed an authenticated user…

All CVEs affecting Github →

Other CWE-502 (Deserialization of Untrusted Data) vulnerabilities

CVE-2026-41104 — Critical (CVSS 10.0): Deserialization of untrusted data in Microsoft Planetary Computer Pro allows an unauthorized attacker to disclose…
CVE-2026-43633 — Critical (CVSS 10.0): HestiaCP versions 1.9.0 through 1.9.4 contain a deserialization vulnerability in the web terminal component caused by a…
CVE-2026-33819 — Critical (CVSS 10.0): Deserialization of untrusted data in Microsoft Bing allows an unauthorized attacker to execute code over a network.
CVE-2026-20131 — Critical (CVSS 10.0): A vulnerability in the web-based management interface of Cisco Secure Firewall Management Center (FMC) Software could…
CVE-2026-25632 — Critical (CVSS 10.0): EPyT-Flow is a Python package designed for the easy generation of hydraulic and water quality scenario data of water…
CVE-2025-14931 — Critical (CVSS 10.0): Hugging Face smolagents Remote Python Executor Deserialization of Untrusted Data Remote Code Execution Vulnerability.…

Browse all CWE-502 (Deserialization of Untrusted Data) vulnerabilities →