CVE-2023-35847: VirtualSquare picoTCP (aka PicoTCP-NG) through 2.1 does not have an MSS lower bound (e.g., it could be zero).

Q: How do I fix CVE-2023-35847?

picotcp: upgrade to newer than 2.1. Exact commands for each OS are on this page.

Q: Is CVE-2023-35847 being exploited?

CVE-2023-35847 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2023-35847 affect?

CVE-2023-35847 affects picotcp. Severity is high (CVSS 7.5). VirtualSquare picoTCP (aka PicoTCP-NG) through 2.1 does not have an MSS lower bound (e.g., it could be zero).

Q: How urgent is CVE-2023-35847?

Priority 45/100. High severity; Remotely exploitable, no login, no user action

This month

HIGH 7.5REMOTEUPGRADE

CVE-2023-35847 is a high-severity flaw (CVSS 7.5) affecting picotcp. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

VirtualSquare picoTCP (aka PicoTCP-NG) through 2.1 does not have an MSS lower bound (e.g., it could be zero).

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 47%)
CISA exploited list	No
Weakness	CWE-908
Published	2023-06-19
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: virtualsquare

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

Am I affected?

Timeline

2023-06-19 03:15 UTCPublished CVE record published
2026-06-17 06:05 UTCUpdated Record last modified

virtualsquare picotcp UPGRADE

Affected: <= 2.1

Fixed in: newer than 2.1

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to newer than 2.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade picotcp

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade picotcp

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

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-2023-35847?

picotcp: upgrade to newer than 2.1. Exact commands for each OS are on this page.

Is CVE-2023-35847 being exploited?

CVE-2023-35847 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-2023-35847 affect?

CVE-2023-35847 affects picotcp. Severity is high (CVSS 7.5). VirtualSquare picoTCP (aka PicoTCP-NG) through 2.1 does not have an MSS lower bound (e.g., it could be zero).

How urgent is CVE-2023-35847?

Priority 45/100. High severity; Remotely exploitable, no login, no user action

Related CVEs

CVE-2023-35849 HIGH 7.5 UPGRADE VirtualSquare picoTCP (aka PicoTCP-NG) through 2.1 does not properly check whether header sizes would result i
CVE-2023-35848 HIGH 7.5 UPGRADE VirtualSquare picoTCP (aka PicoTCP-NG) through 2.1 lacks certain size calculations before attempting to set a
CVE-2023-35846 HIGH 7.5 UPGRADE VirtualSquare picoTCP (aka PicoTCP-NG) through 2.1 does not check the transport layer length in a frame before
CVE-2023-30463 HIGH 7.5 UPGRADE Altran picoTCP through 1.7.0 allows memory corruption (and subsequent denial of service) because of an integer
CVE-2021-33304 CRITICAL 9.8 DOWNGRADE DOWNGRADE Double Free vulnerability in virtualsquare picoTCP v1.7.0 and picoTCP-NG v2.1 in modules/pico_fragments.c in f

References

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