CVE-2018-6651: In the uncurl_ws_accept function in uncurl.c in uncurl before 0.07, as used in Parsec before 140-3, insufficie

Q: How do I fix CVE-2018-6651?

uncurl: upgrade to 0.07; parsec: upgrade to 140-3. Exact commands for each OS are on this page.

Q: Is CVE-2018-6651 being exploited?

CVE-2018-6651 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-2018-6651 affect?

CVE-2018-6651 affects uncurl, parsec. Severity is high (CVSS 8.8). In the uncurl_ws_accept function in uncurl.c in uncurl before 0.07, as used in Parsec before 140-3, insufficient Origin header validation (accepting an arbitrary substring match) for WebSocket API requests allows remote attackers to bypass

This month

HIGH 8.8UPGRADEUPGRADE

CVE-2018-6651 is a high-severity flaw (CVSS 8.8) affecting uncurl, parsec. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In the uncurl_ws_accept function in uncurl.c in uncurl before 0.07, as used in Parsec before 140-3, insufficient Origin header validation (accepting an arbitrary substring match) for WebSocket API requests allows remote attackers to bypass intended access restrictions. In Parsec, this means full control over the victim's computer.

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	2.4% (top 16%)
CISA exploited list	No
Weakness	CWE-352
Published	2018-02-05
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: parsecgaming · uncurl project

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

Am I affected?

Timeline

2018-02-05 22:29 UTCPublished CVE record published
2026-06-17 02:02 UTCUpdated Record last modified

uncurl project uncurl UPGRADE

Affected: < 0.07

Fixed in: 0.07

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 0.07 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade uncurl

Note

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

parsecgaming parsec UPGRADE

Affected: < 140-3

Fixed in: 140-3

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 140-3 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade parsec

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-2018-6651?

uncurl: upgrade to 0.07; parsec: upgrade to 140-3. Exact commands for each OS are on this page.

Is CVE-2018-6651 being exploited?

CVE-2018-6651 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-2018-6651 affect?

CVE-2018-6651 affects uncurl, parsec. Severity is high (CVSS 8.8). In the uncurl_ws_accept function in uncurl.c in uncurl before 0.07, as used in Parsec before 140-3, insufficient Origin header validation (accepting an arbitrary substring match) for WebSocket API requests allows remote attackers to bypass

How urgent is CVE-2018-6651?

Priority 52/100. High severity

References

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