# CVE-2026-91191: Device update mechanism package authentication bypass

Source: https://junglewise.ai/threats/cve-2026-91191-the-device-s-update-mechanism-includes-conditions-that-allow  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-29. Updated: 2026-09-29  
License: CC BY 4.0 with a link back

CVE-2026-91191 · Severity: high · CVSS 7.5 · Published 2026-09-29

A device's software update system fails to properly verify that packages are authentic, allowing an attacker to trick the device into installing malicious software. The vulnerability stems from two issues: the boot process temporarily disables signature checks, and the production signing key was leaked in the public SDK. An attacker can exploit this to execute arbitrary code with root privileges on the device.

Technologies: [<UNKNOWN>](https://junglewise.ai/threats/technologies/x-unknown).

## Quick answers

**Is CVE-2026-91191 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-91191 being exploited in the wild.

**How severe is CVE-2026-91191?** High severity, with a CVSS score of 7.5, published 29 September 2026.

**Which products and versions are affected?** <UNKNOWN>.

**Is there a fix for CVE-2026-91191?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-91191 attacked?** It is attacked over the network, in device firmware.

**Am I affected by CVE-2026-91191?** Check whether you run <UNKNOWN>. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability exploits OPKG configuration that disables signature verification during boot and restores packages from an unsigned feed, combined with exposure of the production private key in the publicly distributed SDK. An attacker can either supply malicious packages during the window when verification is disabled, or forge valid signatures using the exposed private key. This allows code execution with root privileges during package installation without authentication or user interaction beyond a normal update cycle.

## Affected products

- <UNKNOWN>

## Timeline

- 2026-09-29: disclosed

## References

- [https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-272-01.json](https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-272-01.json)
- [https://ltrxdev.atlassian.net/wiki/spaces/LTRXTS/pages/1889828865/Latest+firmware+for+the+G520+Series+G526+G526RP+G527+G528](https://ltrxdev.atlassian.net/wiki/spaces/LTRXTS/pages/1889828865/Latest+firmware+for+the+G520+Series+G526+G526RP+G527+G528)

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