5.3Medium
CVE-2026-100527
OpenClaw before 2026.8.2 contains a denial of service vulnerability in the Browser extension relay that allows unauthenticated network sources to exhaust pending-authentication capacity. Attackers can hold every pending slot by maintaining silent WebSocket upgrades, preventing paired extensions from completing Browser Relay Authentication v2.
What this means for your business
- An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.
- FIRST's prediction model gives it a 0.3% chance of attack attempts being seen in the next 30 days, ranking above 25% of all known flaws.
What to do
- 1Ask your IT team or provider whether any of your systems use the affected product.
- 2If you do, follow the vendor's guidance. No patch reference has been published yet.
Not sure if your company is exposed?
Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.
Scoring
- CVSS
- 5.3 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L- CVSS v4
- 6.9
- Weakness
- CWE-400
- Assigned by
- disclosure@vulncheck.com
Dates
- Published
- 2026-09-26
- Last modified
- 2026-09-26
- Sources
- NVD