CVE-2025-53940

8.5 HIGH 4% exploit odds Fix listed Crypto Server

What it is

Quiet is an alternative to team chat apps like Slack, Discord, and Element that does not require trusting a central server or running one's own. In versions 6.1.0-alpha.4 and below, Quiet's API for backend/frontend communication was using an insecure, not constant-time comparison function for token verification. This allowed for a potential timing attack where an attacker would try different token values and observe tiny differences in the response time (wrong characters fail faster) to guess the whole token one character at a time. This is fixed in version 6.0.1.

At a glance

Exploitability: Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.
Exploit odds: 4.2% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2025-07-24 23:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-06-17 09:39 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 4.2% in the next 30 days (EPSS).
Severity: 8.5 HIGH (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2025-07-24 23:15 UTC
Last modified: 2026-06-17 09:39 UTC
Exploit probability: 4.2% · EPSS, next 30 days
Weakness: CWE-208
Record status: Deferred

Attack profile CVSS 4.0 · 8.5

Attack vector: Local
Complexity: High
Attack requirements: None
Privileges needed: Low
User interaction: None
Confidentiality: High
Integrity: High
Availability: High

Raw vector

CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2025-53940.md and follow it. Check whether this project is affected by CVE-2025-53940. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record