AstroBlocks: Admin session tokens can be forged due to a hard-coded fallback JWT secret and a mismatched environment variable name
Affects AstroBlocks versions before 3.4.0 where CMS_JWT_SECRET was not set, so the public fallback secret was used. No vendor rating is given. Fixed in 3.4.0.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 3.4.0
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 3.4.0.
- Published
- Last modified
- Whether it needs action now or is a reference record, by fixed rules, with why. Last checked is when cve.now last re-read it.What do these mean? →
- Reference
- Last checked
- 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? →
- 27/100 · 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? →
- Unclear
- 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
Affected software is the astro-blocks product from NauelG, a block-first CMS for Astro projects, before version 3.4.0. A remote attacker with no login can forge an admin session token using the public fallback JWT secret that ships in the published package, gaining full control over content, users, media, redirects, and configuration.
Read the original description
AstroBlocks is a block-first CMS for Astro projects. Prior to version 3.4.0, admin session tokens can be forged due to a hard-coded fallback JWT secret and a mismatched environment variable name. An attacker who knows the public fallback value (readable in the published package) can forge a valid session token with role: "owner" and obtain full administrative control of the CMS — creating/deleting content, users, media, redirects, and configuration. This issue has been patched in version 3.4.0.
Who should check
Teams running @astroblocks/astro-blocks before 3.4.0 with the admin UI at /cms enabled, including Astro sites that followed the documented setup
Not fixed by: Setting ASTRO_BLOCKS_JWT_SECRET alone does not protect versions before 3.4.0.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure17/25No login or user action needed, reachable over the network without a login · Unknown: Advisories don't say whether default setups are affected
- 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
- Would score about 32 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 3.4.0.
Workaround: Explicitly set the CMS_JWT_SECRET environment variable to a strong random value of 32+ characters, then rotate it to invalidate any forged tokens.
Check your systems with an agent
Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.
Check whether my systems are affected by CVE-2026-64682 (AstroBlocks: Admin session tokens can be forged due to a hard-coded fallback JWT secret and a mismatched environment variable name), using the cve.now data below. Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only. What cve.now has for CVE-2026-64682 (entry last updated 2026-11-11): Affected: - NauelG astro-blocks: fixed in 3.4.0 Fixed versions: 3.4.0. Conditions (all must be true for the bug to be hit): - Affected versions are all versions prior to 3.4.0 (source: https://github.com/NauelG/astro-blocks/security/advisories/GHSA-mfcg-m7j5-7v72) - Auth was set up by following the documentation, so the documented variable was set but never read (source: https://github.com/NauelG/astro-blocks/security/advisories/GHSA-mfcg-m7j5-7v72) - No CMS_JWT_SECRET was set, so the server used the public fallback secret (source: https://github.com/NauelG/astro-blocks/security/advisories/GHSA-mfcg-m7j5-7v72) Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory. Attacker needs: network access, no login, no user action. Workaround: Explicitly set the CMS_JWT_SECRET environment variable to a strong random value of 32+ characters, then rotate it to invalidate any forged tokens. (source: https://github.com/NauelG/astro-blocks/security/advisories/GHSA-mfcg-m7j5-7v72) CISA KEV: CVE-2026-64682 is not listed as of cve.now's last read. This KEV status is for CVE-2026-64682 only. If you also check another CVE, look up its own KEV status; never assume it from this one. How to check: - Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory. Verify against the linked advisories before concluding, and cite the date you read each one: - https://github.com/NauelG/astro-blocks/security/advisories/GHSA-mfcg-m7j5-7v72 - https://github.com/NauelG/astro-blocks/pull/51 - https://github.com/NauelG/astro-blocks/commit/fd83bf0b37a756363f718e134c16e448da09a74d - https://github.com/NauelG/astro-blocks/releases/tag/v3.4.0 Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing. Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action. Entry: https://cve.now/CVE-2026-64682 For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example get_vulnerability with id CVE-2026-64682.
Timeline
- CVE published
- First seen by cve.now
- Posted on X by cve.now
Affected versions
- NauelG astro-blocks
fixed in 3.4.0
Evidence 6
Vendor advisory · 1
Establishes: Affected and fixed versions.
- Advisory
CVE record · 2
Establishes: The identifier and description.
- Record
- Record
Other links · 3
- Repository
- Repository
- Repository
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-64682
Is CVE-2026-64682 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?
The CMS signs admin session tokens with a secret. When the real secret is not configured, it falls back to a hard-coded public value, so anyone who knows that value can create a valid admin token. The documented variable name also did not match the one the code reads, so setups that followed the docs never supplied the real secret.Source: github.com
Which versions are affected by CVE-2026-64682?
astro-blocks: before 3.4.0.Source: cve.now feed data
Am I affected, and how do I check?
All AstroBlocks versions prior to 3.4.0 are affected. Check the installed version and whether the CMS_JWT_SECRET environment variable is set on the server; if it was never set, the public fallback secret is in use.Source: github.com
How do I fix CVE-2026-64682?
Upgrade to AstroBlocks 3.4.0 or later, which fixes the issue. After upgrading, set CMS_JWT_SECRET to a strong random value of at least 32 characters and rotate it to invalidate any tokens that may have been forged.Source: github.com