CVE-2023-49606: A use-after-free vulnerability exists in the HTTP Connection Headers parsing in Tinyproxy 1.11.1 and Tinyproxy

This week

CRITICAL 9.8REMOTEDOWNGRADE

CVE-2023-49606 is a critical-severity flaw (CVSS 9.8) affecting tinyproxy. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A use-after-free vulnerability exists in the HTTP Connection Headers parsing in Tinyproxy 1.11.1 and Tinyproxy 1.10.0. A specially crafted HTTP header can trigger reuse of previously freed memory, which leads to memory corruption and could lead to remote code execution. An attacker needs to make an unauthenticated HTTP request to trigger this vulnerability.

Why this priority

Critical severity
EPSS top 1%: very likely to be exploited
Public exploit reference
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	63.1% (top 1%)
CISA exploited list	No
Weakness	CWE-416
Published	2024-05-01
Last modified	2026-06-17

Publisher (CNA): Talos · Vendor: tinyproxy project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2024-05-01 16:15 UTCPublished CVE record published
2026-06-17 06:36 UTCUpdated Record last modified

tinyproxy project tinyproxy DOWNGRADE

Affected: 1.10.0 · 1.11.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.10.0

1. Check installed version

apt-cache policy tinyproxy || rpm -q tinyproxy || tinyproxy --version

2. No fixed release: DOWNGRADE to a release before 1.10.0 (Debian / Ubuntu)

apt-cache madison tinyproxy sudo apt install tinyproxy=<VERSION_BEFORE_1.10.0> sudo apt-mark hold tinyproxy

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list tinyproxy sudo dnf downgrade tinyproxy-<VERSION_BEFORE_1.10.0> sudo dnf versionlock add tinyproxy

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.

Fedora 46 · noctalia · FIXED · 5.4.1-1.fc46 · FEDORA-2026-a4755e8ef7 · source

sudo dnf upgrade --advisory=FEDORA-2026-a4755e8ef7

Fedora ELN · efifs · FIXED · 1.13-1.eln159 · FEDORA-2026-3fd0bb7307 · source

sudo dnf upgrade --advisory=FEDORA-2026-3fd0bb7307

Ubuntu 20.04 · tinyproxy · FIXED · 1.10.0-4ubuntu0.2

sudo apt update && sudo apt install --only-upgrade tinyproxy dpkg --compare-versions "$(dpkg-query -W -f='${Version}' tinyproxy)" ge "1.10.0-4ubuntu0.2" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 22.04 · tinyproxy · FIXED · 1.11.0-1ubuntu0.1~esm2

sudo apt update && sudo apt install --only-upgrade tinyproxy dpkg --compare-versions "$(dpkg-query -W -f='${Version}' tinyproxy)" ge "1.11.0-1ubuntu0.1~esm2" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 24.04 · tinyproxy · FIXED · 1.11.1-3ubuntu0.1

sudo apt update && sudo apt install --only-upgrade tinyproxy dpkg --compare-versions "$(dpkg-query -W -f='${Version}' tinyproxy)" ge "1.11.1-3ubuntu0.1" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 24.10 · tinyproxy · FIXED · 1.11.2-1

sudo apt update && sudo apt install --only-upgrade tinyproxy dpkg --compare-versions "$(dpkg-query -W -f='${Version}' tinyproxy)" ge "1.11.2-1" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 25.04 · tinyproxy · FIXED · 1.11.2-1

sudo apt update && sudo apt install --only-upgrade tinyproxy dpkg --compare-versions "$(dpkg-query -W -f='${Version}' tinyproxy)" ge "1.11.2-1" && echo PATCHED || echo STILL-VULNERABLE

Debian 12 · tinyproxy · FIXED · 1.11.1-2.1+deb12u1

sudo apt update && sudo apt install --only-upgrade tinyproxy dpkg --compare-versions "$(dpkg-query -W -f='${Version}' tinyproxy)" ge "1.11.1-2.1+deb12u1" && echo PATCHED || echo STILL-VULNERABLE

Debian 13 · tinyproxy · FIXED · 1.11.1-4

sudo apt update && sudo apt install --only-upgrade tinyproxy dpkg --compare-versions "$(dpkg-query -W -f='${Version}' tinyproxy)" ge "1.11.1-4" && echo PATCHED || echo STILL-VULNERABLE

Alpine 3.20 · tinyproxy · FIXED · tinyproxy-1.11.2-r0

apk add --upgrade tinyproxy apk info -v tinyproxy

Alpine 3.21 · tinyproxy · FIXED · tinyproxy-1.11.2-r0

apk add --upgrade tinyproxy apk info -v tinyproxy

Alpine 3.22 · tinyproxy · FIXED · tinyproxy-1.11.2-r0

apk add --upgrade tinyproxy apk info -v tinyproxy

Alpine 3.23 · tinyproxy · FIXED · tinyproxy-1.11.2-r0

apk add --upgrade tinyproxy apk info -v tinyproxy

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

GitHub PoC: d0rb/CVE-2023-49606 (4 stars)
Write-up: talosintelligence.com/vulnerability_reports/TALOS-2023-1889
Write-up: www.talosintelligence.com/vulnerability_reports/TALOS-2023-1889

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2023-49606?

tinyproxy: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2023-49606 being exploited?

CVE-2023-49606 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2023-49606 affect?

CVE-2023-49606 affects tinyproxy. Severity is critical (CVSS 9.8). A use-after-free vulnerability exists in the HTTP Connection Headers parsing in Tinyproxy 1.11.1 and Tinyproxy 1.10.0. A specially crafted HTTP header can trigger reuse of previously freed memory, which leads to memory corruption and could

How urgent is CVE-2023-49606?

Priority 72/100. Critical severity; EPSS top 1%: very likely to be exploited; Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-31842 HIGH 7.5 UPGRADE Tinyproxy through 1.11.3 is vulnerable to HTTP request parsing desynchronization due to a case-sensitive compa
CVE-2025-63938 MEDIUM 6.5 UPGRADE Tinyproxy through 1.11.2 contains an integer overflow vulnerability in the strip_return_port() function within
CVE-2022-40468 HIGH 7.5 UPGRADE Potential leak of left-over heap data if custom error page templates containing special non-standard variables
CVE-2017-11747 MEDIUM 5.5 UPGRADE main.c in Tinyproxy 1.8.4 and earlier creates a /run/tinyproxy/tinyproxy.pid file after dropping privileges to
CVE-2012-3505 MEDIUM 5.0 UPGRADE Tinyproxy 1.8.3 and earlier allows remote attackers to cause a denial of service (CPU and memory consumption)

References

← Back to latest CVEs