makeplane up to 1.2.x fetch_and_encode_favicon server-side request forgery

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.8$0-$5k0.00

Summaryinfo

A vulnerability was found in makeplane plane up to 1.2.x and classified as critical. This vulnerability affects the function fetch_and_encode_favicon. Such manipulation leads to server-side request forgery. This vulnerability is uniquely identified as CVE-2026-39843. The attack can be launched remotely. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in makeplane plane up to 1.2.x and classified as critical. Affected by this issue is the function fetch_and_encode_favicon. The manipulation with an unknown input leads to a server-side request forgery vulnerability. Using CWE to declare the problem leads to CWE-918. 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. Impacted is confidentiality, integrity, and availability. CVE summarizes:

Plane is an an open-source project management tool. From 0.28.0 to before 1.3.0, the remediation of GHSA-jcc6-f9v6-f7jw is incomplete which could lead to the same full read Server-Side Request Forgery when a normal html page contains a link tag with an href that redirects to a private IP address is supplied to Add link by an authenticated attacker with low privileges. Redirects for the main page URL are validated, but not the favicon fetch path. fetch_and_encode_favicon() still uses requests.get(favicon_url, ...) with the default redirect-following. This vulnerability is fixed in 1.3.0.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-39843 since 04/07/2026. The exploitation is known to be easy. The attack may be launched remotely. There are known technical details, but no exploit is available.

Upgrading to version 1.3.0 eliminates this vulnerability.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.0
VulDB Meta Temp Score: 6.8

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.7
CNA Vector (GitHub_M): 🔒

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Server-side request forgery
CWE: CWE-918
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: plane 1.3.0

Timelineinfo

04/07/2026 CVE reserved
04/09/2026 +2 days Advisory disclosed
04/09/2026 +0 days VulDB entry created
04/09/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-39843 (🔒)
GCVE (CVE): GCVE-0-2026-39843
GCVE (VulDB): GCVE-100-356612

Entryinfo

Created: 04/09/2026 18:16
Changes: 04/09/2026 18:16 (64)
Complete: 🔍
Cache ID: 216:BDD:103

Once again VulDB remains the best source for vulnerability data.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Do you need the next level of professionalism?

Upgrade your account now!