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). A crafted chunk size such as 0x7fffffffffffffff (LONG_MAX) bypasses the existing validation check (chunklen < 0), leading to a signed integer overflow during arithmetic operations (chunklen + 2). This results in incorrect size calculations, causing the proxy to attempt reading an extremely large amount of request-body data and holding worker connections open indefinitely. An attacker can exploit this behavior to exhaust all available worker slots, preventing new connections from being accepted and causing complete service unavailability. Upstream addressed this issue in commit bb7edc4; however, the latest stable release (1.11.3) remains affected at the time of publication.
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Mon, 30 Mar 2026 15:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Mon, 30 Mar 2026 07:30:00 +0000

Type Values Removed Values Added
Description 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). A crafted chunk size such as 0x7fffffffffffffff (LONG_MAX) bypasses the existing validation check (chunklen < 0), leading to a signed integer overflow during arithmetic operations (chunklen + 2). This results in incorrect size calculations, causing the proxy to attempt reading an extremely large amount of request-body data and holding worker connections open indefinitely. An attacker can exploit this behavior to exhaust all available worker slots, preventing new connections from being accepted and causing complete service unavailability. Upstream addressed this issue in commit bb7edc4; however, the latest stable release (1.11.3) remains affected at the time of publication.
Weaknesses CWE-190
References
Metrics cvssV2_0

{'score': 7.8, 'vector': 'AV:N/AC:L/Au:N/C:N/I:N/A:C'}

cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: TuranSec

Published:

Updated: 2026-03-30T15:02:33.584Z

Reserved: 2026-03-11T08:30:57.837Z

Link: CVE-2026-3945

cve-icon Vulnrichment

Updated: 2026-03-30T15:02:22.371Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-03-30T08:16:17.653

Modified: 2026-03-30T13:26:07.647

Link: CVE-2026-3945

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses