Integer overflow in Tinyproxy

CVE-2026-3945

An integer overflow vulnerability in the HTTP chunked transfer encoding parser in tinyproxy up to and including version 1.11.3 allows an unauthenticated remote attacker to cause a denial of service (DoS). The issue occurs because chunk size values are parsed using strtol without properly validating overflow conditions (e.g., errno == ERANGE).

Vulnerability class: Integer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.010 (62.5th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 62nd percentile — 62.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-3945: held from 0.006 to 0.010.

EPSS over last 30 days · oldest: 0.006 · newest: 0.010 · change: +0.005

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-3945?
CVE-2026-3945 is a high-severity vulnerability in Tinyproxy, classified under Integer Overflow or Wraparound. CVSS score: 7.5/10. Published 2026-03-30.
How severe is CVE-2026-3945?
High severity. CVSS v3 base score is 7.5 out of 10.