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Fencer Vulns
high 7.5

CVE-2022-35923 json

Inefficient Regular Expression Complexity in v8n

published 2022-08-02 4 y ago modified 2026-06-17 4 mo ago also GHSA-xrx9-gj26-5wx9 , EUVD-2022-7187

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.8%
EPSS 1.8% chance of exploitation in 30 days, percentile 78%
public exploits
0
none known

Summary

v8n is a javascript validation library. Versions of v8n prior to 1.5.1 were found to have an inefficient regular expression complexity in the `lowercase()` and `uppercase()` regex which could lead to a denial of service attack. In testing of the `lowercase()` function a payload of 'a' + 'a'.repeat(i) + 'A' with 32 leading characters took 29443 ms to execute. The same issue happens with uppercase(). Users are advised to upgrade. There are no known workarounds for this issue.

Patch / fix

  • npm v8n 1.5.1
  • v8n_project v8n 1.5.1

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
18 mo ago

Exploit prediction

1.76% chance of exploitation in the next 30 days, higher than 78% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • huntr.dev https://huntr.dev/bounties/2d92f644-593b-43b4-bfd1-c8042ac60609/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
npm v8n
<1.5.1
1.5.1

Affected products

  • imbrn v8n

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption
  • CWE-1333 Inefficient Regular Expression Complexity

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.