VulnerabilityPublished 22 Jan 2026

CVE-2026-20888: Gitea Open Source Git Server · Improper Access Control

Affects Gitea Open Source Git ServerSource CVE Database V5

Not known to be exploited · CVSS 4.3 Medium.

Data as of 26 Oct 2026, 09:16 UTC

CVSS 3.1 base score

4.3Medium

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

EPSS: 0.3% chance of exploitation in 30 days – higher than 25% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: None
Availability: None

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

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, 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: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 22 Jan 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
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), the Metasploit, Exploit-DB and nuclei-templates index as of 26 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC 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
GiteaGitea Open Source Git Server	Affected <=1.25.3	Fixed in–
Gogithub.com/go-gitea/gitea`pkg:golang/github.com/go-gitea/gitea`Other threats	Affected =0	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Organizations should immediately audit user permissions within Gitea, ensuring that read access users do not have unintended capabilities to affect merge operations. Implement strict role-based access control (RBAC) policies that clearly separate read-only users from those authorized to manage merges. Monitor and log all auto-merge scheduling and cancellation activities to detect unauthorized attempts. Until an official patch is released, consider restricting auto-merge features to trusted users only or disabling auto-merge scheduling if feasible. Additionally, integrate code review and merge approval processes outside of Gitea’s auto-merge functionality to maintain control over code integration. Stay informed on updates from the Gitea project and apply patches promptly once available.

Description

CVE-2026-20888 is a medium severity vulnerability in the Gitea Open Source Git Server where improper access control allows users with read access to pull requests to cancel scheduled auto-merges initiated by other users. This flaw arises from insufficient authorization checks in the web interface when handling auto-merge cancellations. Exploitation does not require user interaction but does require at least read-level privileges. The vulnerability impacts the integrity of the development workflow by enabling unauthorized interference with merge operations, though it does not affect confidentiality or availability. No known exploits are currently reported in the wild. European organizations using Gitea for source code management should review their access control policies and update or patch affected versions once fixes are available.

Impact

For European organizations, this vulnerability could disrupt software development workflows by allowing unauthorized users to cancel auto-merges, potentially delaying feature integration and bug fixes. While it does not directly compromise source code confidentiality or availability, the integrity of the development process is at risk, which could lead to operational inefficiencies and increased risk of human error or malicious interference. Organizations relying heavily on Gitea for collaborative development, especially those with complex CI/CD pipelines, may face challenges in maintaining codebase stability. This could be particularly impactful for sectors with stringent software quality requirements such as finance, healthcare, and critical infrastructure. The vulnerability may also erode trust among development teams if unauthorized actions go undetected.

Summary

CVE-2026-20888 is an access control vulnerability identified in the Gitea Open Source Git Server, specifically concerning the cancellation of scheduled auto-merges via the web interface. The root cause is improper authorization verification, which allows users who have only read access to pull requests to cancel auto-merges scheduled by other users. This violates the principle of least privilege and undermines the integrity of the software development lifecycle. The vulnerability is categorized under CWE-284 (Improper Access Control) and CWE-862 (Missing Authorization). The CVSS 3.1 base score is 4.3 (medium), reflecting that the attack vector is network-based, requires low privileges, and no user interaction is needed. The impact is limited to a confidentiality loss (minimal) with no direct impact on integrity or availability, as the attacker cannot modify code or disrupt service but can interfere with merge operations. No patches or exploits are currently documented, but the issue requires attention to prevent workflow disruption and potential trust issues in code integration processes.

CWE-284Improper Access Control (opens in a new tab)
Pillar weaknessCWE Top 25 (2025): #19OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Operation
Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
Architecture and Design · Separation of Privilege
Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
OWASP Cheat Sheets
Docker Security (opens in a new tab)
Third Party Javascript Management (opens in a new tab)
Virtual Patching (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V1.4.4 (opens in a new tab)
V1.4.5 (opens in a new tab)
V1.10.1 (opens in a new tab)
Attack patterns
Embedding Scripts within Scripts (opens in a new tab)
Modification of Windows Service Configuration (opens in a new tab)
Malicious Root Certificate (opens in a new tab)
Intent Spoof (opens in a new tab)
WebView Exposure (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-862Missing Authorization (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #4OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product does not perform an authorization check when an actor attempts to access a resource or perform an action.
Architecture and Design
Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries.
Architecture and Design
Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.8 (opens in a new tab)
V13.4.2 (opens in a new tab)
V7.2.2 (opens in a new tab)
Attack patterns
Exploitation of Thunderbolt Protection Flaws (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 30 Jan 2026, 09:56 UTC

WeaknessesCWE-284, CWE-862

Technical details

References

Community reviews

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