Severity by source
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/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
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Primary rating from NVD.
CVSS VectorNVD
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/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
Lifecycle Timeline
4DescriptionCVE.org
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.
AnalysisAI
Remote denial of service in tinyproxy versions through 1.11.3 allows unauthenticated attackers to exhaust all proxy worker connections via malformed HTTP chunked transfer encoding. An integer overflow in chunk size parsing (using strtol() without ERANGE validation) enables attackers to send LONG_MAX values that bypass size checks and trigger arithmetic overflow during chunklen+2 calculations. This forces the proxy to attempt reading unbounded request body data, holding worker slots indefinitely until all connections are exhausted and new clients are rejected. Upstream fix available (commits bb7edc4, 969852c) but latest stable release 1.11.3 remains unpatched. EPSS data not available; no public exploit identified at time of analysis, though attack complexity is low (CVSS AC:L) and requires no authentication (PR:N).
Same weakness CWE-190 – Integer Overflow or Wraparound
View allSame technique Integer Overflow
View allVendor StatusVendor
Debian
| Release | Status | Fixed Version | Urgency |
|---|---|---|---|
| bullseye | vulnerable | 1.10.0-5 | - |
| bullseye (security) | vulnerable | 1.10.0-5+deb11u1 | - |
| bookworm, bookworm (security) | vulnerable | 1.11.1-2.1+deb12u1 | - |
| trixie | vulnerable | 1.11.2-1 | - |
| forky, sid | vulnerable | 1.11.3-1 | - |
| (unstable) | fixed | (unfixed) | - |
SUSE
Severity: HighShare
External POC / Exploit Code
Leaving vuln.today
EUVD-2026-17066
GHSA-6vhj-8f7g-v7f7