CVEs / CVE-2024-2511

CVE-2024-2511: OpenSSL OpenSSL vulnerability

• medium 5.9 CVSS 3.1 (from the CNA)
• EPSS 59.3% chance of exploitation in the next 30 days, higher than 99% of CVEs (8 Nov 2026)
• Last changed at its sources 8 Nov 2026

Description

Issue summary: Some non-default TLS server configurations can cause unbounded memory growth when processing TLSv1.3 sessions Impact summary: An attacker may exploit certain server configurations to trigger unbounded memory growth that would lead to a Denial of Service This problem can occur in TLSv1.3 if the non-default SSL_OP_NO_TICKET option is being used (but not if early_data support is also configured and the default anti-replay protection is in use). In this case, under certain conditions, the session cache can get into an incorrect state and it will fail to flush properly as it fills. The session cache will continue to grow in an unbounded manner. A malicious client could deliberately create the scenario for this failure to force a Denial of Service. It may also happen by accident in normal operation. This issue only affects TLS servers supporting TLSv1.3. It does not affect TLS clients. The FIPS modules in 3.2, 3.1 and 3.0 are not affected by this issue. OpenSSL 1.0.2 is also not affected by this issue.

Affected and fixed versions

Exploitation

Not in the CISA Known Exploited Vulnerabilities catalog as of 6 Nov 2026.

Severity

References

• CVE-2024-2511 on NVD
• CVE-2024-2511 on OSV
• https://github.com/openssl/openssl/commit/7e4d731b1c07201ad9374c1cd9ac5263bdf35bce Patch
• https://github.com/openssl/openssl/commit/b52867a9f618bb955bed2a3ce3db4d4f97ed8e5d Patch
• https://github.com/openssl/openssl/commit/e9d7083e241670332e0443da0f0d4ffb52829f08 Patch
• https://github.openssl.org/openssl/extended-releases/commit/5f8d25770ae6437db119dfc951e207271a326640 Permissions Required
• https://www.openssl.org/news/secadv/20240408.txt Vendor Advisory
• http://www.openwall.com/lists/oss-security/2024/04/08/5 Mailing List, Third Party Advisory
• https://lists.debian.org/debian-lts-announce/2024/10/msg00033.html Mailing List, Third Party Advisory
• https://lists.debian.org/debian-lts-announce/2024/11/msg00000.html Mailing List, Third Party Advisory
• https://security.netapp.com/advisory/ntap-20240503-0013/ Third Party Advisory
• https://cert-portal.siemens.com/productcert/html/ssa-265688.html Third Party Advisory
• https://cert-portal.siemens.com/productcert/html/ssa-354112.html Third Party Advisory
• https://cert-portal.siemens.com/productcert/html/ssa-398330.html Third Party Advisory
• https://cert-portal.siemens.com/productcert/html/ssa-613116.html Third Party Advisory
• https://cert-portal.siemens.com/productcert/html/ssa-769027.html Third Party Advisory
• https://cert-portal.siemens.com/productcert/html/ssa-915275.html Third Party Advisory