CVE-2023-27533
HIGHEPSS 79th pctlDescription
A vulnerability in input validation exists in curl <8.0 during communication using the TELNET protocol may allow an attacker to pass on maliciously crafted user name and "telnet options" during server negotiation. The lack of proper input scrubbing allows an attacker to send content or perform option negotiation without the application's intent. This vulnerability could be exploited if an application allows user input, thereby enabling attackers to execute arbitrary code on the system.
How to fix
This vulnerability affects an unusually large number of packages. The highest-confidence fixes are shown above; the full list is longer. Check the referenced advisories for complete coverage.
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Exploit Intelligence
Elevated risk: more likely to be exploited than 79% of all known CVEs.
References
Related Vulnerabilities
Other CWE-75 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2021-22911 | Critical | 9.8 | 95% | - | - |
| CVE-2024-0801 | High | 7.5 | 42% | - | - |
| CVE-2021-39174 | High | 8.8 | 3.9% | - | Fix |
| CVE-2023-40743 | Critical | 9.8 | 2.6% | - | Fix |
| CVE-2026-29042 | Critical | 9.8 | 2.3% | - | Fix |
| CVE-2021-22910 | Critical | 9.8 | 2.3% | - | Fix |
Common questions
How do I fix CVE-2023-27533?
Published advisories record a fix for 147 affected products. The "How to fix" section on this page lists the fixed version and source advisory for each one, so apply the entry matching what you actually run.
Is CVE-2023-27533 being actively exploited?
Not that we know of. CVE-2023-27533 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 2.0% is the estimated probability that it will be exploited in the next 30 days. That is higher than 79% of all scored CVEs.
How severe is CVE-2023-27533?
CVE-2023-27533 has a CVSS v3 base score of 8.8, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2023-27533 affect?
Published advisories record a fix for curl (Debian), curl (Red Hat / RHEL), curl (Rocky), curl-debuginfo (Red Hat / RHEL), and 143 more. Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
Embed a live status badge for CVE-2023-27533
Markdown
[](https://tridentstack.com/cve/CVE-2023-27533)HTML
<a href="https://tridentstack.com/cve/CVE-2023-27533"><img src="https://tridentstack.com/cve/badge/CVE-2023-27533.svg" alt="CVE-2023-27533"></a>Find and fix vulnerabilities across your fleet
TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.
This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-02-13.