GitHub Enterprise Server up to 3.20.0 incorrect regex

Summaryinfo

A vulnerability was found in GitHub Enterprise Server up to 3.20.0 and classified as critical. This affects an unknown function. The manipulation results in incorrect regex. This vulnerability is known as CVE-2026-4296. It is possible to launch the attack remotely. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical has been found in GitHub Enterprise Server up to 3.20.0. Affected is an unknown code. The manipulation with an unknown input leads to a incorrect regex vulnerability. CWE is classifying the issue as CWE-185. The product specifies a regular expression in a way that causes data to be improperly matched or compared. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

An incorrect regular expression vulnerability was identified in GitHub Enterprise Server that allowed an attacker to bypass OAuth redirect URI validation. An attacker with knowledge of a first-party OAuth application's registered callback URL could craft a malicious authorization link that, when clicked by a victim, would redirect the OAuth authorization code to an attacker-controlled domain. This could allow the attacker to gain unauthorized access to the victim's account with the scopes granted to the OAuth application. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.20.1, 3.19.5, 3.18.8, 3.17.14, 3.16.17, 3.15.21, 3.14.26. This vulnerability was reported via the GitHub Bug Bounty program.

The weakness was published by ahacker1 and hacktron. The advisory is shared for download at docs.github.com. This vulnerability is traded as CVE-2026-4296 since 03/16/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. There are neither technical details nor an exploit publicly available.

Upgrading eliminates this vulnerability.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Bug Tracking Software

Vendor

• GitHub

Name

• Enterprise Server

Version

• 3.0
• 3.1
• 3.2
• 3.3
• 3.4
• 3.5
• 3.6
• 3.7
• 3.8
• 3.9
• 3.10
• 3.11
• 3.12
• 3.13
• 3.14
• 3.14.0
• 3.14.1
• 3.14.2
• 3.14.3
• 3.14.4
• 3.14.5
• 3.14.6
• 3.14.7
• 3.14.8
• 3.14.9
• 3.14.10
• 3.14.11
• 3.14.12
• 3.14.13
• 3.14.14
• 3.14.15
• 3.14.16
• 3.14.17
• 3.14.18
• 3.14.19
• 3.14.20
• 3.14.21
• 3.14.22
• 3.14.23
• 3.14.24
• 3.14.25
• 3.15
• 3.15.0
• 3.15.1
• 3.15.2
• 3.15.3
• 3.15.4
• 3.15.5
• 3.15.6
• 3.15.7
• 3.15.8
• 3.15.9
• 3.15.10
• 3.15.11
• 3.15.12
• 3.15.13
• 3.15.14
• 3.15.15
• 3.15.16
• 3.15.17
• 3.15.18
• 3.15.19
• 3.15.20
• 3.16
• 3.16.0
• 3.16.1
• 3.16.2
• 3.16.3
• 3.16.4
• 3.16.5
• 3.16.6
• 3.16.7
• 3.16.8
• 3.16.9
• 3.16.10
• 3.16.11
• 3.16.12
• 3.16.13
• 3.16.14
• 3.16.15
• 3.16.16
• 3.17
• 3.17.0
• 3.17.1
• 3.17.2
• 3.17.3
• 3.17.4
• 3.17.5
• 3.17.6
• 3.17.7
• 3.17.8
• 3.17.9
• 3.17.10
• 3.17.11
• 3.17.12
• 3.17.13
• 3.18
• 3.18.0
• 3.18.1
• 3.18.2
• 3.18.3
• 3.18.4
• 3.18.5
• 3.18.6
• 3.18.7
• 3.19
• 3.19.0
• 3.19.1
• 3.19.2
• 3.19.3
• 3.19.4
• 3.20.0

License

• open-source

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Once again VulDB remains the best source for vulnerability data.

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