SB2026082679 - Ubuntu update for openssl
Published: August 26, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 4 vulnerabilities.
1) Resource exhaustion (CVE-ID: CVE-2024-2511)
CWE-ID: CWE-400 - Resource exhaustion
CVSSv4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to unbounded memory growth when processing TLSv1.3 sessions. A remote attacker can trigger resource exhaustion and perform a denial of service (DoS) attack.
Successful exploitation of the vulnerability requires that the non-default SSL_OP_NO_TICKET option is being used in TLSv1.3.
2) Out-of-bounds read (CVE-ID: CVE-2024-5535)
CWE-ID: CWE-125 - Out-of-bounds read
CVSSv4: 6.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a boundary condition within the SSL_select_next_proto() function when using NPN. A remote attacker can send specially crafted data to the application, trigger an out-of-bounds read and perform a denial of service (DoS) attack.
3) Asymmetric Resource Consumption (Amplification) (CVE-ID: CVE-2026-54874)
CWE-ID: CWE-405 - Asymmetric Resource Consumption (Amplification)
CVSSv4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to asymmetric resource consumption in DTLS record buffering when receiving future-epoch records during a handshake in progress. A remote attacker can send numerous small forged DTLS records claiming to belong to the next epoch to cause a denial of service.
Up to 100 such records may be buffered per connection, retaining around 1.7 megabytes of memory because the implementation keeps the entire read buffer for each buffered record.
4) Out-of-bounds write (CVE-ID: CVE-2026-63072)
CWE-ID: CWE-787 - Out-of-bounds write
CVSSv4: 6.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to out-of-bounds write in OpenSSL CMS decryption key unwrapping logic when decrypting a crafted CMS message through CMS_decrypt(). A remote attacker can supply a crafted CMS message to cause a denial of service.
The issue causes a deterministic 8-byte heap write immediately past the allocation when the key-wrap OID is changed to select the padded variant.
Remediation
Install update from vendor's website.