CVE-2026-77791
Apache Tomcat: DoS via busy wait during WebSocket close
02 Description
Apache Tomcat: DoS via busy wait during WebSocket close
03 Exploitation and scoring
- 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.
- AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
- Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
- EPSS probability
- 0.67% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 52.0% of scored records. A rank, not a probability.
- NVD base score
- 7.5 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVD analysis status
- Awaiting Analysis. NVD last modified this record on 2026-09-23.
- Red Hat severity
- Important. 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.
04 Metadata
- Published
- 2026-09-23 11:20Z1 MO AGO
- Last updated
- 2026-09-23 18:10Z1 MO AGO
- Reserved
- 2026-08-21
- Assigning CNA
- apache
- Record state
- PUBLISHED
- Severity
- High (CVSS 7.5)
- CNA CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weaknesses
- Data version
- 5.2
- Document digest
- 7f9b1d5690ce5b45573a738babff6fcb551bc1248b185787ae4551d153332d64
05 Affected products
06 References
- lists.apache.orghttps://lists.apache.org/thread/mb1pjjooqytrl6hbvbt3rw1lqwlon4cz
- www.openwall.comhttp://www.openwall.com/lists/oss-security/2026/09/23/24
07 Fixed in
Debian 12
- tomcat10 No fix yet
- tomcat9 Fixed in 9.0.70-2
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 13
- tomcat10 No fix yet
- tomcat11 No fix yet
- tomcat9 Fixed in 9.0.70-2
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- tomcat10 Fixed in 10.1.60-1
- tomcat11 No fix yet
- tomcat9 Fixed in 9.0.70-2
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 24.04 LTS
- tomcat10 No fix yet
- tomcat9 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 26.04 LTS
- tomcat10 No fix yet
- tomcat11 No fix yet
- tomcat9 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 26.10
- tomcat10 No fix yet
- tomcat11 No fix yet
- tomcat9 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 14.04 LTS
- tomcat6 No fix yet
- tomcat7 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 16.04 LTS
- tomcat7 No fix yet
- tomcat8 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 18.04 LTS
- tomcat8 No fix yet
- tomcat9 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 20.04 LTS
- tomcat9 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 22.04 LTS
- tomcat9 No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.