Chartbrew: Full account takeover via JWTs accepted under default CB_SECRET
Affects Chartbrew server up to 5.2.2 installed from source or docker-compose with CB_SECRET left at its shipped default. Fixed in 5.2.3.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 5.2.3
- Who is exposed
- Default setups
Do first: Check every install: default setups are affected.
- Last modified
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 32/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Default setups
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
Chartbrew, an open-source web app for building charts from databases and APIs, is affected when its session tokens can be forged, which an attacker can do remotely without logging in when the CB_SECRET value is known, weak, or the shipped default, as in stock source or repository Docker Compose installs. Such an attacker can impersonate any user, bypassing their password and two-factor authentication, and use that user's Chartbrew privileges across the API and socket layer.
Read the original description
Chartbrew is an open-source web application that can connect directly to databases and APIs and use the data to create charts. Prior to 5.2.3, four authentication helpers accepted session tokens signed with CB_SECRET, including known, weak, or shipped-default values. The vulnerable surface is session JWT fallback in server/modules/verifyToken.js, verifyUser.js, getUserFromToken.js, and socketManager.js across the API and socket layer. A stock source or repository Docker Compose deployment retains a known, weak, or default CB_SECRET and an attacker submits a forged HS256 token decoding to a target user id. Knowing the symmetric secret lets the attacker create a token that the legacy verification fallback accepts as the target user without that user's password or two-factor authentication. The condition includes stock source and repository Docker Compose installs and any otherwise known or weak CB_SECRET; a bare container where CB_SECRET is undefined is not affected by this fallback path. A forged session impersonates the chosen user across the entire API and socket layer and exercises that user's Chartbrew privileges. This issue is fixed in version 5.2.3.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure22/25Default setups, reachable over the network without a login
- Reach?/20Unknown. No tracked technology or package matched
- Severity9.8/10CVSS 9.8
- No patch0/5No signal
What would change the score
- Would score about 72 if added to CISA KEV
- Would score about 67 if CISA's SSVC rates exploitation active
What to do
Check every install: default setups are affected.
Upgrade to a fixed version: 5.2.3.
Timeline
- CVE published
- First seen by cve.now
- Posted on X by cve.now
Affected versions
- chartbrew chartbrew
fixed in 5.2.3
Evidence 3
- Advisory
- Repository
- Repository
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-85295
Is CVE-2026-85295 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
Chartbrew accepts JWTs signed with a secret that is publicly known when CB_SECRET is left at its default. A forged token gives a full session as any user ID, which allows reading, changing, and deleting that user's data while bypassing password and 2FA.Source: github.com
Which versions are affected by CVE-2026-85295?
chartbrew: before 5.2.3.Source: cve.now feed data
Am I affected, and how do I check?
Chartbrew server up to v5.2.2 is affected when CB_SECRET is the shipped default change_to_random_string or another known or weak value. Stock source and repo docker-compose installs ship with this default, so check the CB_SECRET value in your .env file.Source: github.com
How do I fix CVE-2026-85295?
Upgrade the Chartbrew server to 5.2.3 or later. Set CB_SECRET to a unique random value rather than the shipped default.Source: github.com