Issabel Framework: Use of Hard-coded Cryptographic Key
CVE-2026-89026 is a critical-severity use of hard-coded cryptographic key vulnerability in Issabel Framework from Issabel Foundation, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version b97dbaf0b71c1c36f841e672b664afbeb02773bd as the first without the flaw, so updating Issabel Framework to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 2.7% chance of exploitation within 30 days, higher than 86% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Issabel Framework to b97dbaf0b71c1c36f841e672b664afbeb02773bd or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Issabel Foundation | Issabel Framework | before b97dbaf0b71c1c36f841e672b664afbeb02773bd | b97dbaf0b71c1c36f841e672b664afbeb02773bd |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (vulncheck.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 9.3 | Critical | CNA (vulncheck.com) |
| CVSS 3.1 | 9.8 | Critical | CNA (vulncheck.com) |
Official description
The Issabel Framework, the web framework supporting Issabel PBX software, before commit b97dbaf contains a hard-coded HS256 JWT signing key in the pbxapi index.php file that is identical across every installation, allowing unauthenticated remote attackers to forge valid bearer tokens. Attackers can use the forged token to call the manager originate endpoint with the System application parameter, causing Asterisk to execute arbitrary OS commands as the Asterisk user. Exploitation evidence was first observed by the Shadowserver Foundation on 2026-09-09.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use of Hard-coded Cryptographic Key
The product uses a hard-coded, unchangeable cryptographic key.
How developers prevent this class of flaw
- Prevention schemes mirror that of hard-coded password storage.
More Use of Hard-coded Cryptographic Key vulnerabilities (CWE-321)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other references
Recent Use of Hard-coded Cryptographic Key vulnerabilities
- 9.8 Critical severity
- 9.8 Critical severity
- 9.1 Critical severity
- 7.8 High severity
- 7.7 High severity
- 8.8 High severity
Spotted an error? Tell us.