CVE-2026-59998: openbsd openssh
CVSS: 6.5v3.1MediumAnalyzed
AliasesALPINE-CVE-2026-59998UBUNTU-CVE-2026-59998DEBIAN-CVE-2026-59998
Published 08-07-2026Last modified 08-07-2026
Vulnerability summary
CVE-2026-59998 is a medium (CVSS 6.5) vulnerability in openbsd openssh. EPSS estimates a 0.18% chance of exploitation in the next 30 days, higher than 7% of scored vulnerabilities.
CVSS score
6.5/10
010
Medium · v3.1 (NVD)EPSS score
0.18%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 7 · Related 5Timeline
- 08-07-2026PublishedVulnerability first disclosed.
- 08-07-2026Last modifiedVulnerability information updated.
Description
sshd in OpenSSH before 10.4 has an undocumented security-relevant behavior: GSSAPIStrictAcceptorCheck has no value if the server is in Windows Active Directory.
CVSS metrics
5 scores · 5 sources · 1 versionMedium 6.5Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:NSources5 sources · 4.8–6.5
- CVE.orgCNA4.8MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:NDiffers
- OSV · AlpineEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
- OSV · UbuntuEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
- OSV · DebianEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
EPSS trend
Probability
0.18%
Chance of exploitation in the next 30 days
Percentile
7%
Versus all other CVEs
30-day change
0.00 pp
From 0.18% on 19-09-2026
19-09-202619-10-2026
EPSS score0.18%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu2 products
- openssh< 1:6.6p1-2ubuntu2.13+esm4 | < 1:7.2p2-4ubuntu2.10+esm10 | All versions (No fix recorded) | < 1:7.6p1-4ubuntu0.7+esm6 | < 1:8.2p1-4ubuntu0.13+esm3 | < 1:8.9p1-3ubuntu0.16 | < 1:8.9p1-3ubuntu0.16+Fips3 | < 1:9.6p1-3ubuntu13.18 | < 1:9.6p1-3ubuntu13.18+Fips1 | < 1:10.2p1-2ubuntu3.4
- openssh-ssh1All versions (No fix recorded)
Alpine1 product
- openssh< 10.3_p1-r1
Debian1 product
- opensshAll versions (No fix recorded) | < 1:10.4p1-1
Openbsd1 product
- openssh< 10.4
4 vendors · 5 products
References
9 links- marc.info?l=openssh-unix-dev&m=178333966933090&w=2Release Notes
