Skip to content
Fencer Vulns
high 8.1

CVE-2026-22665 json

prompts.chat Identity Confusion via Case-Sensitive Username Handling

published 2026-04-03 7 mo ago modified 2026-11-08 19 h ago also EUVD-2026-18829

cvss
8.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 27%
public exploits
0
none known

Summary

prompts.chat prior to commit 1464475, contains an identity confusion vulnerability due to inconsistent case-sensitive and case-insensitive handling of usernames across write and read paths, allowing attackers to create case-variant usernames that bypass uniqueness checks. Attackers can exploit non-deterministic username resolution to impersonate victim accounts, replace profile content on canonical URLs, and inject attacker-controlled metadata and content across the platform.

Patch / fix

  • fka prompts.chat 2026-03-24

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
7 mo ago

Exploit prediction

0.34% chance of exploitation in the next 30 days, higher than 27% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/f/prompts.chat/pull/1098 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 8.6 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
CNA 3.1 8.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
CNA 4.0 8.6 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/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

Affected products

  • f prompts.chat

Classification

Weakness
  • CWE-178 Improper Handling of Case Sensitivity

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.