CVE-2026-54387

criticalpriority · track · 0EPSS 0.004 · 38 %ileDEEU
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
0.44% (38th) EPSS
CVSS 9.1 · critical
Is it mine?
7 products
Check your exposure
Who says so?
3 sources
cnnvd · enisa_euvd · cert_bund

EPSS · scored 2026-10-28

Tinyproxy through 1.11.3, fixed in commit ff45d3b, fails to reconcile conflicting Content-Length and Transfer-Encoding: chunked headers, forwarding both verbatim to the backend while using Content-Length to determine how many request body bytes to consume. Remote attackers can desynchronize the proxy and backend parser state, allowing injection of arbitrary HTTP requests to the backend to enable cache poisoning, access control bypass, and request hijacking.

01

cvss

Technical severity, 0–10. One row per scoring source.

9.3
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 8–9.3

v3.19.1criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Nsecondary · disclosure@vulncheck.comexploitability 3.9 · impact 5.2
v4.09.3criticalCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:Nsecondary · ENISA EU
v4.09.3criticalCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/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:Xsecondary · disclosure@vulncheck.com
v4.08highCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/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:Xsecondary · CVSS-BT (t0sche)
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: totalcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-444US
04

affected products (7)

Products and version ranges known to be affected.

05

advisories (1)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2026-1999Tinyproxy: Mehrere SchwachstellenDeutsch2026-06-17csaf · cert_bundDE

    Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Tinyproxy ausnutzen, um Dateien zu manipulieren und Sicherheitsmaßnahmen zu umgehen.

06

also known as (3)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

cnnvdenisa_euvdcert_bundNVDCVE.orgMITRE
published 2026-06-17modified 2026-07-14
08

references (12)

External citations — patches, advisories, analysis.

scry

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