CVE-2026-91187: dashbit nimble_zta · Improper Verification of Cryptographic Signature
Affects dashbit nimble_ztaSource CVE Database V5
Not known to be exploited · CVSS 9.3 Critical : upgrade to 0.1.3 as a priority.
Data as of 8 Nov 2026, 23:24 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 23% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 0.1.3, 6458fd18a5ba41166d4973214c519e98fe05b72d
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:H/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 24 Sep 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 8 Nov 2026.
What to do
Upgrade nimble_zta to 0.1.3; nimble_zta to 6458fd18a5ba41166d4973214c519e98fe05b72d.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| dashbitnimble_zta | Affected
| Fixed in
|
| dashbitnimble_zta | Affected
| Fixed in
|
Hexnimble_ztapkg:hex/nimble_ztaOther threats | Affected
| Fixed in
|
CPE configurations (1)
cpe:2.3:a:dashbit:nimble_zta:*:*:*:*:*:*:*:*
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch is available for this vulnerability. Users should upgrade nimble_zta to version 0.1.3 or later to remediate the issue. Since this is a cloud service integration, the vendor manages remediation for the cloud-hosted service, but local application dependencies must be updated accordingly. Check the vendor advisory for the latest remediation guidance.
Description
Improper Verification of Cryptographic Signature vulnerability in dashbit nimble_zta allows an unauthenticated remote attacker to authenticate as an arbitrary Cloudflare service token. Applications using the Cloudflare Zero Trust authentication strategy are affected. verify_token/2 in lib/nimble_zta/cloudflare.ex matches the result of JOSE.JWT.verify/2 against {_, token, _s}, which discards the boolean verification result and returns the decoded token after a failed signature check. The attacker sends a forged JWT in the cf-access-jwt-assertion header, carrying the expected iss claim and the seven service token claims. verify_iss/2 reads the iss claim from the forged token, so it rejects nothing, and the service token path then returns those claims as the authenticated identity. This issue affects nimble_zta: from 0.1.2 before 0.1.3.
References
- github.com/dashbitco/nimble_zta/security/advisories/GHSA-rj24-g8cc-g7g2 (opens in a new tab)
- cna.erlef.org/cves/CVE-2026-91187.html (opens in a new tab)
- osv.dev/vulnerability/EEF-CVE-2026-91187 (opens in a new tab)
- github.com/dashbitco/nimble_zta/commit/bc004b70985ae5763901baab3a4e204047899768 (opens in a new tab)
- github.com/dashbitco/nimble_zta/commit/6458fd18a5ba41166d4973214c519e98fe05b72d (opens in a new tab)