November 14, 2026

CVE Watchtower

CVE-2026-125371tinyproxy tinyproxy

NVD

Vulnerability Summary

Tinyproxy through 1.11.3 contains an access control bypass vulnerability in acl_string_processing() in src/acl.c that compares only trailing hostname characters without checking DNS label boundaries. Attackers controlling the PTR record for their source IP, such as untrusted.net, can satisfy an 'Allow trusted.net' entry to use the proxy despite deny-by-default ACLs.
Severity Level
MEDIUM(6.3)
Published Date
Nov 9, 2026
Last Modified
Nov 10, 2026
Exploitation Status
No confirmed exploitation yet
EPSS Score (30-Day)
0.28%Probability
Root Weakness (CWE)
CWE-187 ↗
See the MITRE CWE entry for the full definition of this weakness.
CVSS v4.0 Base Metrics — Score 6.3 (MEDIUM)
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
Attack VectorNetwork
Attack ComplexityHigh
Attack RequirementsPresent
Privileges RequiredNone
User InteractionNone
Confidentiality (Vulnerable System)Low
Integrity (Vulnerable System)Low
Availability (Vulnerable System)None
Confidentiality (Subsequent System)None
Integrity (Subsequent System)None
Availability (Subsequent System)None
Show CVSS v3.x metrics (score 4.8)
CVSS v3.1 Base Metrics — Score 4.8 (MEDIUM)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
Attack VectorNetwork
Attack ComplexityHigh
Privileges RequiredNone
User InteractionNone
ScopeUnchanged
ConfidentialityLow
IntegrityLow
AvailabilityNone

Affected & Patched Versions

Affected Versions
  • tinyproxy tinyproxy <= 1.11.3
Patched Versions
  • tinyproxy tinyproxy 1.11.3

What to do

Fix it during your normal patch cycle. No exploitation is confirmed yet.

  1. Check whether you run tinyproxy tinyproxy and which version.
  2. Update to a patched version listed above, then confirm the new version.

Timeline

  • Nov 9, 2026Published
  • Nov 10, 2026Record last modified

Score, severity and exploitation changes are tracked from the day Watchtower started logging them.

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External References

Data last checked: Nov 14, 2026 00:39 UTC