CVE-2017-18365Github Insecure Deserialization
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.
Published Mar 28, 2019 · Updated Nov 21, 2024
Key Facts
Patch immediately- CVE-2017-18365 is a critical-severity vulnerability (CVSS 9.8 v3) affecting Github.
- It is exploited in the wild, listed in Industry KEV feed since Nov 10, 2025. Public exploit code is available.
- EPSS estimates a 21% probability of exploitation in the next 30 days.
- Fixed versions are available, including Github 2.8.7.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
Scores
CVSS v3
9.8
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
21%
Higher than 97.5% of all scored CVEs
Exploit maturity
Weaponized
ATLAS score
49/100
Publication score, see How it works
Exploitation Verdict
KEV listed
Nov 10, 2025
Federal due date
None
No federal due date
Ransomware use
Not reported
Attributed actors
None named
Exploit & Defence Guidance
Exploit maturity
Weaponized
Public exploit code
1
Proof-of-concept links
In-the-wild evidence
2
Reports of active use
Advisories And Exploit References
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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| Industry KEV feed | Nov 10, 2025 | n/a | Not reported |
Affected Products
2 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| GithubGithub | 2.8.7 | 2.8.7 |
Patched Releases
Github
2.8.7
Timeline
Publicly disclosed
Mar 28, 2019
Last updated
Nov 21, 2024
Added to Industry KEV feed
Nov 10, 2025
Weakness Type
- CWE-502 Deserialization of Untrusted Data
References
FAQ
Common Questions.
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.
Affected: Github versions 2.8.7. The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed since Nov 10, 2025.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including Github 2.8.7.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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