VulnerabilityPublished 10 Mar 2026

CVE-2026-3306: GitHub Enterprise Server · Insecure Direct Object Reference

Affects GitHub Enterprise ServerSource CVE Database V5

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Not known to be exploited · CVSS 5.3 Medium · fixed in 3.14.24 : update GitHub Enterprise Server when convenient.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 4.0 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 31% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 3.14.24

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: Low
User Interaction: None
Vulnerable system confidentiality: None
Vulnerable system integrity: Low
Vulnerable system availability: None
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: Low: The attacker requires privileges that provide basic capabilities that are typically limited to settings and resources owned by a single low-privileged user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact to the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 10 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
Public exploit code: GitHub proofs of concept
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), GitHub proofs of concept, the Metasploit, Exploit-DB and nuclei-templates index as of 24 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
GitHubEnterprise Server	Affected >=3.14.0 <3.14.24 >=3.15.0 <3.15.19 >=3.16.0 <3.16.15 >=3.17.0 <3.17.12 >=3.18.0 <3.18.6 >=3.19.0 <3.19.3	Fixed in–

AI-suggested

To mitigate CVE-2026-3306, organizations should immediately upgrade GitHub Enterprise Server to one of the patched versions: 3.14.24, 3.15.19, 3.16.15, 3.17.12, 3.18.6, or 3.19.3. In addition to patching, administrators should audit user permissions to ensure the principle of least privilege is enforced, limiting write access to projects only to trusted users. Monitoring and logging project metadata changes can help detect unauthorized modifications. Implementing strict access controls and regular reviews of project boards and issue trackers can reduce the risk of unnoticed tampering. Organizations should also educate users about the importance of safeguarding their credentials to prevent account compromise. Finally, integrating automated security tools that detect anomalous changes in project metadata or unusual user activity can provide early warning signs of exploitation attempts.

Description

CVE-2026-3306 is an authorization bypass vulnerability in GitHub Enterprise Server affecting versions 3.14.0 through 3.19.0. It allows a user with read access to a repository and write access to a project to modify issue and pull request metadata without proper repository write permissions. The flaw occurs when adding an existing item to a project, where column value updates are applied without verifying the actor's repository write permissions. This vulnerability was responsibly disclosed via GitHub's Bug Bounty program and fixed in versions 3.14.24, 3.

Impact

The primary impact of CVE-2026-3306 is the unauthorized modification of issue and pull request metadata within GitHub Enterprise Server projects. This can lead to inaccurate project tracking, misrepresentation of issue or pull request status, and potential disruption of development workflows. While it does not directly expose source code or allow code execution, the integrity compromise can undermine trust in project data and cause confusion among development teams. Organizations with strict compliance or audit requirements may face challenges if project metadata is altered without proper authorization. Additionally, attackers could leverage this flaw to manipulate project priorities or hide critical issues, indirectly affecting the security posture or release timelines. Since the vulnerability requires only read access to repositories and write access to projects, it expands the threat surface to users with limited privileges, increasing the risk of insider threats or compromised accounts being exploited. The lack of known exploits reduces immediate risk but does not eliminate the potential for future abuse.

CWE-639Authorization Bypass Through User-Controlled Key (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #24OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.
Architecture and Design
For each and every data access, ensure that the user has sufficient privilege to access the record that is being requested.
Architecture and Design · Implementation
Make sure that the key that is used in the lookup of a specific user's record is not controllable externally by the user or that any tampering can be detected.
Architecture and Design
Use encryption in order to make it more difficult to guess other legitimate values of the key or associate a digital signature with the key so that the server can verify that there has been no tampering.
OWASP Cheat Sheets
Access Control (opens in a new tab)
Authorization Testing Automation (opens in a new tab)
Cross-Site Request Forgery Prevention (opens in a new tab)
Insecure Direct Object Reference Prevention (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V4.1.2 (opens in a new tab)
V4.2.1 (opens in a new tab)
V8.3.8 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 17 Mar 2026, 19:08 UTC

WeaknessesCWE-639

Technical details

References

Community reviews

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