CVE-2019-18678

mediumpriority · track · 23EPSS 0.062 · 93 %ileDEEURUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

6.20% (93rd) EPSS

CVSS 5 · medium

Is it mine?

32 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

An issue was discovered in Squid 3.x and 4.x through 4.8. It allows attackers to smuggle HTTP requests through frontend software to a Squid instance that splits the HTTP Request pipeline differently. The resulting Response messages corrupt caches (between a client and Squid) with attacker-controlled content at arbitrary URLs. Effects are isolated to software between the attacker client and Squid. There are no effects on Squid itself, nor on any upstream servers. The issue is related to a request header containing whitespace between a header name and a colon.

cvss

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

5.3

010

base score 0–10 · higher = more severe · hover a vector to decode

v2.05mediumAV:N/AC:L/Au:N/C:N/I:P/A:Nprimary · NVD / NIST USexploitability 10 · impact 2.9

v3.15.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:Nprimary · NVD / NIST USexploitability 3.9 · impact 1.4

v2.05mediumAV:N/AC:L/Au:N/C:N/I:P/A:Nsecondary · FSTEC (BDU) RU

v3.14.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-444USprimaryCWE-444US

affected products (32)

Products and version ranges known to be affected.

Amazon Linux 2all versionscert_bundDEcpe:/o:amazon:linux_2:-
Debian Linuxall versionscert_bundDEcpe:/o:debian:debian_linux:-
Open Source Arch Linuxall versionscert_bundDEcpe:/o:archlinux:archlinux:-
Red Hat Enterprise Linuxall versionscert_bundDEcpe:/o:redhat:enterprise_linux:-
SUSE Linuxall versionscert_bundDEcpe:/o:suse:suse_linux:-
Ubuntu Linuxall versionscert_bundDEcpe:/o:canonical:ubuntu_linux:-
n/a n/a≤ n/aenisa_euvdEU
Canonical Ltd. Ubuntu≤ 19.04fstec_bduRU
Canonical Ltd. Ubuntu≤ 16.04 LTSfstec_bduRU
Canonical Ltd. Ubuntu≤ 18.04 LTSfstec_bduRU
Canonical Ltd. Ubuntu≤ 19.10fstec_bduRU
Fedora Project Fedora≤ 31fstec_bduRU
Fedora Project Fedora≤ 30fstec_bduRU
Squid Software Foundation Squid3.0 → 3.5.28fstec_bduRU
Squid Software Foundation Squid4.0 → 4.8fstec_bduRU
АО «ИВК» Альт 8 СПall versionsfstec_bduRU
АО «Концерн ВНИИНС» ОС ОН «Стрелец»≤ 16.01.2023fstec_bduRU
ООО «РусБИТех-Астра» Astra Linux Common Edition≤ 2.12 «Орёл»fstec_bduRU
ООО «РусБИТех-Астра» Astra Linux Special Edition≤ 1.6 «Смоленск»fstec_bduRU
ООО «РусБИТех-Астра» Astra Linux Special Edition для «Эльбрус»≤ 8.1 «Ленинград»fstec_bduRU

showing 20 of 32

advisories (1)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2023-1391Squid: Mehrere SchwachstellenDeutsch2019-11-06csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Squid ausnutzen, um beliebigen Programmcode auszuführen, um Informationen offenzulegen und um Anfragen zu manipulieren.

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cert_bund NVD CVE.org MITRE

published 2019-11-26modified 2026-06-17

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Related entries.

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+548 more

references (63)

External citations — patches, advisories, analysis.

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