Medium 5.9Published Apr 8, 2024

CVE-2024-2511Unbounded memory growth with session handling in TLSv1.3

Updated under an hour ago (Oct 27, 2026, 8:30 AM ET)

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It affects OpenSSL and 31 other products. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

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.

CVSS: 5.9 MEDIUM (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): CWE-1325
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: openssl
NVD analysis: Deferred
Record last updated: Oct 14, 2026
First seen by InfoSec Signals: Oct 14, 2026

Affected products

Affected products

OpenSSL OpenSSL openssl:openssl (from the name)	from 3.2.0 before 3.2.2; from 3.1.0 before 3.1.6; from 3.0.0 before 3.0.14; from 1.1.1 before 1.1.1y	CNA record
Siemens RUGGEDCOM RM1224 LTE(4G) EU siemens:ruggedcom_rm1224_lte_4g_eu (from the name)	before V8.2	CISA ADP
Siemens RUGGEDCOM RM1224 LTE(4G) NAM siemens:ruggedcom_rm1224_lte_4g_nam (from the name)	before V8.2	CISA ADP
Siemens RUGGEDCOM RST2428P siemens:ruggedcom_rst2428p (from the name)	before V3.1	CISA ADP
Siemens SCALANCE M804PB siemens:scalance_m804pb (from the name)	before V8.2	CISA ADP
Siemens SCALANCE M812-1 ADSL-Router siemens:scalance_m812_1_adsl_router (from the name)	before V8.2	CISA ADP
Siemens SCALANCE M816-1 ADSL-Router siemens:scalance_m816_1_adsl_router (from the name)	before V8.2	CISA ADP
Siemens SCALANCE M826-2 SHDSL-Router siemens:scalance_m826_2_shdsl_router (from the name)	before V8.2	CISA ADP
Siemens SCALANCE M874-2 siemens:scalance_m874_2 (from the name)	before V8.2	CISA ADP
Siemens SCALANCE M874-3 siemens:scalance_m874_3 (from the name)	before V8.2	CISA ADP
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References

References

https://www.openssl.org/news/secadv/20240408.txt	vendor-advisory
https://github.com/openssl/openssl/commit/e9d7083e241670332e0443da0f0d4ffb52829f08	patch
https://github.com/openssl/openssl/commit/7e4d731b1c07201ad9374c1cd9ac5263bdf35bce	patch
https://github.com/openssl/openssl/commit/b52867a9f618bb955bed2a3ce3db4d4f97ed8e5d	patch
https://github.openssl.org/openssl/extended-releases/commit/5f8d25770ae6437db119dfc951e207271a326640	patch
http://www.openwall.com/lists/oss-security/2024/04/08/5
https://lists.debian.org/debian-lts-announce/2024/10/msg00033.html
https://lists.debian.org/debian-lts-announce/2024/11/msg00000.html
https://security.netapp.com/advisory/ntap-20240503-0013/
https://cert-portal.siemens.com/productcert/html/ssa-265688.html
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The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.