CVE-2025-66199

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.42% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 34.7% of scored records. A rank, not a probability.

NVD base score

5.9 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

NVD analysis status

Analyzed. NVD last modified this record on 2026-06-17.

Red Hat severity

Low. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-01-27 16:01Z7 MO AGO

Last updated

2026-01-29 15:03Z7 MO AGO

Reserved

2025-11-24

Assigning CNA

openssl

Record state

PUBLISHED

Severity

Medium (CVSS 5.9)

CNA CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Weaknesses

• CWE-789Memory Allocation with Excessive Size ValueVariant
• CWE-770Allocation of Resources Without Limits or ThrottlingBase

Data version

5.2

Document digest

1690ae3727d50dfc224d877026c34802f69289057acd6175a5739ffadcd12377

• openssl-library.orgOpenSSL Advisoryhttps://openssl-library.org/news/secadv/20260127.txtvendor-advisory
• github.com3.6.1 git commithttps://github.com/openssl/openssl/commit/6184a4fb08ee6d7bca570d931a4e8bef40b64451patch
• github.com3.5.5 git commithttps://github.com/openssl/openssl/commit/895150b5e021d16b52fb32b97e1dd12f20448be5patch
• github.com3.4.4 git commithttps://github.com/openssl/openssl/commit/966a2478046c311ed7dae50c457d0db4cafbf7e4patch
• github.com3.3.6 git commithttps://github.com/openssl/openssl/commit/3ed1f75249932b155eef993a8e66a99cb98bfef4patch