Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade') Affecting openssl package, versions [3.5.0,3.5.6)[3.6.0,3.6.2)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-CONAN-OPENSSL-15520214
- published13 Mar 2026
- disclosed13 Mar 2026
- creditViktor Dukhovni
Introduced: 13 Mar 2026
CVE-2026-2673 (opens in a new tab)How to fix?
Upgrade openssl to version 3.5.6, 3.6.2 or higher.
Overview
Affected versions of this package are vulnerable to Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade') in the TLS 1.3 server key agreement group selection when the server configuration includes the 'DEFAULT' keyword. An attacker can influence the negotiation to use a less preferred key agreement group by manipulating the client's initial keyshare predictions, potentially resulting in the use of weaker or unintended cryptographic groups.
Note:
No OpenSSL FIPS modules are affected by this issue, the code in question lies outside the FIPS boundary.