CVE-2026-3945Network attack vector

Service exhaustion via oversized chunk length

Published Mar 30, 2026 · Updated Mar 30, 2026

Integer overflow in Tinyproxy 1.11.3 and earlier allows remote attackers to exhaust worker slots through oversized HTTP chunks. The pull_client_data_chunked function in src/reqs.c parses a hexadecimal chunk length with strtol, checks only for negative values, then adds 2 without bounding large positive results. Any unauthenticated client able to send chunked requests can hold workers waiting for an enormous body until no slots remain, interrupting new proxy connections.

CVSS severity8.7
High
EPSS probability0.58%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer overflow in Tinyproxy 1.11.3 and earlier allows remote attackers to exhaust worker slots through oversized HTTP chunks. The pull_client_data_chunked function in src/reqs.c parses a hexadecimal chunk length with strtol, checks only for negative values, then adds 2 without bounding large positive results. Any unauthenticated client able to send chunked requests can hold workers waiting for an enormous body until no slots remain, interrupting new proxy connections.

The record

CVE
CVE-2026-3945
Published
Mar 30, 2026
Updated
Mar 30, 2026
Vendor
Tinyproxy
Product
Tinyproxy
Classifications
CWE-190, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 30, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 30, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=<=1.11.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Tinyproxy · Tinyproxyversion=<=1.11.3

Published CVSS scores

7.8TuranSecAV:N/AC:L/Au:N/C:N/I:N/A:C
7.5TuranSecCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
8.7TuranSecCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-190Integer Overflow or Wraparound
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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