CVE-2025-15468: NULL dereference in SSL_CIPHER_find() function on unknown cipher ID

Is it exploited?

Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of 29 Oct 2026. If CISA adds it, this page shows it as known exploited.

How likely is exploitation in the next 30 days?

0.8%

EPSS score, percentile 57.1 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?

5.9 Medium

CVSS v3.1 base score, from CISA's enrichment of the record

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

Advisories and patches (5)

Which versions are affected?

Affected

• from 3.6.0 to before 3.6.1
• from 3.5.0 to before 3.5.5
• from 3.4.0 to before 3.4.4
• from 3.3.0 to before 3.3.6

Versions by product

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026; CVE List, as of 29 Oct 2026. About the data.

What to do

Advisories and patches

• 3.6.1 git commit (Patch)
• 3.5.5 git commit (Patch)
• 3.4.4 git commit (Patch)
• 3.3.6 git commit (Patch)
• OpenSSL Advisory (Vendor advisory)

This summary is based on the CVE record as of 29 Oct 2026. Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

As listed in the CVE record.

Versions not listed are: unaffected.

Source: CVE List, as of 29 Oct 2026. About the data.

About this vulnerability

Issue summary: If an application using the SSL_CIPHER_find() function in a QUIC protocol client or server receives an unknown cipher suite from the peer, a NULL dereference occurs. Impact summary: A NULL pointer dereference leads to abnormal termination of the running process causing Denial of Service. Some applications call SSL_CIPHER_find() from the client_hello_cb callback on the cipher ID r…

Summary: CVE record, as of 29 Oct 2026.

• CISA has not added CVE-2025-15468 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
• The CVE record was published on 27 Jan 2026.
• The CVE record carries a CVSS v3.1 base score of 5.9 (Medium), taken from CISA's enrichment of the record.
• FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.8% (percentile 57.1), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
• CISA's SSVC assessment in the CVE record: exploitation none, automatable no, technical impact partial.
• The credits in the CVE record name AISLE as finder.

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; CVE List, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026. About the data.

Description

NULL dereference in SSL_CIPHER_find() function on unknown cipher ID

Issue summary: If an application using the SSL_CIPHER_find() function in a QUIC protocol client or server receives an unknown cipher suite from the peer, a NULL dereference occurs. Impact summary: A NULL pointer dereference leads to abnormal termination of the running process causing Denial of Service. Some applications call SSL_CIPHER_find() from the client_hello_cb callback on the cipher ID received from the peer. If this is done with an SSL object implementing the QUIC protocol, NULL pointer dereference will happen if the examined cipher ID is unknown or unsupported. As it is not very common to call this function in applications using the QUIC protocol and the worst outcome is Denial of Service, the issue was assessed as Low severity. The vulnerable code was introduced in the 3.2 version with the addition of the QUIC protocol support. The FIPS modules in 3.6, 3.5, 3.4 and 3.3 are not affected by this issue, as the QUIC implementation is outside the OpenSSL FIPS module boundary. OpenSSL 3.6, 3.5, 3.4 and 3.3 are vulnerable to this issue. OpenSSL 3.0, 1.1.1 and 1.0.2 are not affected by this issue.

Source: CVE List, as of 29 Oct 2026. About the data.

Timeline

Known exploited OpenSSL vulnerabilities

• CVE-2014-0160: OpenSSL Information Disclosure Vulnerability (added 4 May 2022)