CVE-2019-8460
Reuven Plevinsky and Tal Vainshtein of Check Point Software Technologies Ltd. discovered that...
OpenBSD kernel version <= 6.5 can be forced to create long chains of TCP SACK holes that causes very expensive calls to tcp_sack_option() for every incoming SACK packet which can lead to a denial of service.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
OpenBSD kernel version <= 6.5 can be forced to create long chains of TCP SACK holes that causes very expensive calls to tcp_sack_option() for every incoming SACK packet which can lead to a denial of service.
- Record
CVE-2019-8460- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:N/A:P - Weakness
- CWE-1049
- Updated
- 2026-11-02
CVE List No score
OpenBSD kernel version <= 6.5 can be forced to create long chains of TCP SACK holes that causes very expensive calls to tcp_sack_option() for every incoming SACK packet which can lead to a denial of service.
- Record
CVE-2019-8460- Weakness
- CWE-1049
- Updated
- 2026-11-02
EUVDEUVD-2019-17850 No score
OpenBSD kernel version <= 6.5 can be forced to create long chains of TCP SACK holes that causes very expensive calls to tcp_sack_option() for every incoming SACK packet which can lead to a denial of service.
- Record
EUVD-2019-17850- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-9q38-5hh6-p5gw
Reuven Plevinsky and Tal Vainshtein of Check Point Software Technologies Ltd. discovered that...
Reuven Plevinsky and Tal Vainshtein of Check Point Software Technologies Ltd. discovered that OpenBSD kernel (all versions, including 6.5) can be forced to create long chains of TCP SACK holes that cause very expensive calls to tcp_sack_option() for every incoming SACK packet which can lead to a denial of service.
- Record
GHSA-9q38-5hh6-p5gw- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-1049
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2019-8460 is a high vulnerability (CVSS 7.5) in Openbsd, published August 26, 2019. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.25%, the 83rd percentile. No source names a fixed version.
References
github.com/openbsd/src/commit/ed8fdce754a5d8d14c09e989d8877707bd43906f
ftp.openbsd.org/pub/OpenBSD/patches/6.5/common/006_tcpsack.patch.sig
security.netapp.com/advisory/ntap-20190905-0001
research.checkpoint.com/tcp-sack-security-issue-in-openbsd-cve-2019-8460
us-cert.cisa.gov/ics/advisories/icsa-19-253-03
nvd.nist.gov/vuln/detail/CVE-2019-8460