CVE-2026-59850: libssh Use After Free
CVSS: 7.5v3.1HighModified
AliasesUBUNTU-CVE-2026-59850DEBIAN-CVE-2026-59850CGA-4m5f-rqjr-74xpCGA-f732-77xp-7m5qCGA-gmgf-r297-9cccCGA-jwvw-3jpg-chm5CGA-m4xc-67vv-fcg3CGA-pv6j-c5pw-mwh9
Published 21-07-2026Last modified 01-09-2026
Vulnerability summary
CVE-2026-59850 is a high (CVSS 7.5) Use After Free vulnerability in libssh. EPSS estimates a 0.35% chance of exploitation in the next 30 days, higher than 26.6% of scored vulnerabilities.
CVSS score
7.5/10
010
High · v3.1 (NVD)EPSS score
0.35%
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 16 · Related 12MGASA-2026-0425OPENSUSE-SU-2026:11377-1OPENSUSE-SU-2026:21444-1RHSA-2026:42922RHSA-2026:55855RHSA-2026:62217RHSA-2026:62218SUSE-SU-2026:22940-1SUSE-SU-2026:22948-1SUSE-SU-2026:22956-1SUSE-SU-2026:23056-1SUSE-SU-2026:23168-1SUSE-SU-2026:3302-1SUSE-SU-2026:3330-1SUSE-SU-2026:3463-1USN-8699-1CGA-4XW5-83FX-46CQ
Timeline
- 21-07-2026PublishedVulnerability first disclosed.
- 01-09-2026Last modifiedVulnerability information updated.
Description
A flaw was found in libssh. If data packets are processed after a channel is closed, channel data callbacks can be invoked after the associated data has already been freed, leading to crashes or possible use-after-free conditions.
CVSS metrics
4 scores · 4 sources · 1 versionHigh 7.5Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HSources4 sources · 4.3–7.5
- CVE.orgCNA4.3MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:LDiffers
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.35%
Chance of exploitation in the next 30 days
Percentile
27%
Versus all other CVEs
30-day change
0.00 pp
From 0.35% on 19-09-2026
19-09-202619-10-2026
EPSS score0.35%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Chainguard3 products
- libssh< 0.12.1-r0
- libssh-dev< 0.12.1-r0
- libssh2All versions (No fix recorded)
Wolfi3 products
- libssh< 0.12.1-r0
- libssh-dev< 0.12.1-r0
- libssh2All versions (No fix recorded)
Redhat2 products
- enterprise_linux8.0 | 9.0 | 10.0
- hardened_imagesna
Debian1 product
- libsshAll versions (No fix recorded) | < 0.11.5-0+deb13u1 | < 0.12.1-1
Libssh1 product
- libsshna
Ubuntu1 product
- libsshAll versions (No fix recorded) | < 0.9.6-2ubuntu0.22.04.8 | < 0.10.6-2ubuntu0.5 | < 0.11.3-1ubuntu2.1
6 vendors · 11 products
