CVE-2026-77638

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 ImpacttotalSuccessful exploitation gives total 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

0.29% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 22.3% of scored records. A rank, not a probability.

NVD base score

9.0 (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:C/C:H/I:H/A:H

NVD analysis status

Analyzed. NVD last modified this record on 2026-10-18.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

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

2026-08-20 20:52Z2 MO AGO

Last updated

2026-08-27 16:06Z2 MO AGO

Reserved

2026-08-20

Assigning CNA

mitre

Record state

PUBLISHED

Severity

High (CVSS 8.9)

CNA CVSS vector

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

Weaknesses

• CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')Class

Data version

5.2

Document digest

5486f91822934d0e88778265b2003ee362d9c6fb29615e80434d882d19208999

• gitlab.torproject.orghttps://gitlab.torproject.org/tpo/core/tor/-/raw/tor-0.4.9.11/ChangeLog