CVE-2026-59847: libssh Incorrect Check of Function Return Value
CVSS: 7.5v3.1HighAnalyzed
AliasesUBUNTU-CVE-2026-59847DEBIAN-CVE-2026-59847CGA-33h3-rgxf-qc7cCGA-3f89-449h-364mCGA-hv3r-2gcg-gm76CGA-jrmj-p3pc-cj6fCGA-p9c9-rwwp-6c5jCGA-vpmw-jx93-8vmg
Published 21-07-2026Last modified 01-09-2026
Vulnerability summary
CVE-2026-59847 is a high (CVSS 7.5) Incorrect Check of Function Return Value vulnerability in libssh. EPSS estimates a 0.33% chance of exploitation in the next 30 days, higher than 24.9% of scored vulnerabilities.
CVSS score
7.5/10
010
High · v3.1 (NVD)EPSS score
0.33%
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-V4CC-8CP3-WGR7
Timeline
- 21-07-2026PublishedVulnerability first disclosed.
- 01-09-2026Last modifiedVulnerability information updated.
Description
A flaw was found in libssh. Incorrect AES-GCM finalization checks in builds using the OpenSSL backend can effectively remove integrity protection, allowing an in-path attacker to modify plaintext on the wire without detection.
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:H/A:NSources4 sources · 5.9–7.5
- CVE.orgCNA5.9MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:NDiffers
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS trend
Probability
0.33%
Chance of exploitation in the next 30 days
Percentile
25%
Versus all other CVEs
30-day change
0.00 pp
From 0.33% on 18-09-2026
18-09-202618-10-2026
EPSS score0.33%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-253Incorrect Check of Function Return ValueThe product incorrectly checks a return value from a function, which prevents it from detecting errors or exceptional conditions.
- CWE-1310Missing Ability to Patch ROM CodeMissing an ability to patch ROM code may leave a System or System-on-Chip (SoC) in a vulnerable state.
Affected 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
- libssh≥ 0.9.0, < 0.11.5 | 0.12.0
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
