VulnerabilityPublished 24 Mar 2026

CVE-2026-33679: vikunja · Server-Side Request Forgery (SSRF)

Affects vikunjaSource CVE Database V5

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Not known to be exploited · CVSS 6.4 Medium : upgrade to 2.2.1 when convenient.

Data as of 29 Oct 2026, 19:04 UTC

CVSS 3.1 base score

6.4Medium

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

EPSS: 0.4% chance of exploitation in 30 days – higher than 34% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 2.2.1

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

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

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: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
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: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 24 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 29 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

Upgrade vikunja and github.com/go-vikunja/vikunja to 2.2.1.

Affected software

Product	Affected	Fixed in
go-vikunjavikunja	Affected <2.2.1	Fixed in 2.2.1
Gogithub.com/go-vikunja/vikunja`pkg:golang/github.com/go-vikunja/vikunja`Other threats	Affected <2.2.1	Fixed in 2.2.1

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

AI-suggested

Upgrade all Vikunja instances to version 2.2.1 or later, where the vulnerability is patched.
Implement strict validation and sanitization of URLs obtained from untrusted sources such as OIDC claims before making HTTP requests. Use allowlists to restrict requests to trusted domains only.
Employ network segmentation and firewall rules to prevent application servers from accessing sensitive internal or cloud metadata endpoints.
Use SSRF protection libraries or middleware that enforce safe HTTP client usage and prevent requests to private IP ranges or known metadata IPs.
Monitor application logs for unusual outbound HTTP requests, especially to internal IP ranges or cloud metadata URLs.
Review and restrict OIDC provider configurations to limit the ability of users to specify arbitrary picture URLs.
Conduct regular security assessments and penetration tests focusing on SSRF and related vulnerabilities in web applications.

Description

Vikunja is an open-source self-hosted task management platform. Prior to version 2.2.1, the `DownloadImage` function in `pkg/utils/avatar.go` uses a bare `http.Client{}` with no SSRF protection when downloading user avatar images from the OpenID Connect `picture` claim URL. An attacker who controls their OIDC profile picture URL can force the Vikunja server to make HTTP GET requests to arbitrary internal or cloud metadata endpoints. This bypasses the SSRF protections that are correctly applied to the webhook system. Version 2.2.1 patches the issue.

Impact

The primary impact of CVE-2026-33679 is unauthorized internal network reconnaissance and potential leakage of sensitive metadata from cloud environments. Attackers exploiting this SSRF can access internal services that are not exposed externally, such as cloud instance metadata endpoints, which may contain credentials or configuration data. This can lead to further compromise of cloud resources or lateral movement within an organization's network. The vulnerability can also cause partial denial of service if internal services are overwhelmed by crafted requests. Since the vulnerability requires only low privileges and no user interaction, it poses a moderate risk to organizations running vulnerable versions of Vikunja, especially those deployed in cloud or hybrid environments. However, the impact on data integrity is low, and the overall severity is medium due to limited scope and exploit complexity. Organizations with sensitive internal services accessible only via internal networks are at higher risk.

CWE-918Server-Side Request Forgery (opens in a new tab)
Base weaknessCWE Top 25 (2025): #22OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.
Implementation · Operation
If there is a known list of applications, IP, hostname, and/or domains to which the product is allowed to communicate, then use allowlists to ensure that outgoing requests are restricted to these known entities. The allowlists could be in the application code or possibly enforced by firewalls or network segmentation.
Implementation · Operation
If the product is expected to be able to connect to arbitrary IP addresses or domains, consider using a denylist that includes private network addresses, internal domain names, etc. The denylist could be in the application code or possibly enforced by firewalls or network segmentation.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
OWASP Cheat Sheets
Server Side Request Forgery Prevention (opens in a new tab)
Unvalidated Redirects and Forwards (opens in a new tab)
Cross Site Scripting Prevention (opens in a new tab)
DOM based XSS Prevention (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V12.6.1 (opens in a new tab)
V5.2.6 (opens in a new tab)
Attack patterns
Server Side Request Forgery (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 24 Mar 2026, 16:17 UTC

WeaknessesCWE-918

Technical details

References

Community reviews

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