CVE-2026-59842
Libssh: libssh: information disclosure via short gssapi curve25519 public key
No known exploitation. EPSS puts it in the 40th percentile. A vendor fix is available.
What to do
The vendor has published a fix. Version details are below where the sources state them.
What it is
From the CVE record
A flaw was found in libssh. During server-side GSSAPI key exchange, a client-supplied Curve25519 public key shorter than the expected length is copied without proper length validation, leading to an out-of-bounds heap read. This could allow a remote unauthenticated attacker to disclose small amounts of server memory.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
0.5% chance of exploitation activity in the next 30 days, which ranks it in the 40th percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
22 events over 63 days, from the signal feeds we watch.
- Patch availableworkaround available, record updated
- Patch availableworkaround available, record updated
- Patch availableworkaround available, record updated
- OpenVAS check added
- Workaround availableworkaround available, record updated, record updated
- Workaround availableworkaround available, workaround available, published, weakness classified, att&ck mapped, record updated, record updated
Affected products
- Red Hat Enterprise Linux 10Operating Systems / linux-distro
- Red Hat Hardened ImagesOperating Systems / linux-distro
- hardened imagesOperating Systems / linux-distro
- enterprise linux for elsOperating Systems / linux-distro
- enterprise linux for eusOperating Systems / linux-distro
- enterprise linux for ibm z systemsOperating Systems / linux-distro
- enterprise linux for ibm z systems elsOperating Systems / linux-distro
- enterprise linux for ibm z systems eusOperating Systems / linux-distro
And 6 more affected products. See all after sign-in
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
Scored 3.7 by NVD.
How it is reached
- Attack Vector NetworkExploitable remotely over the network without any special conditions
- Attack Complexity HighRequires specific conditions like a race condition or non-default configuration
- Privileges Required NoneNo authentication required — anyone can exploit this
- User Interaction NoneNo user interaction needed — fully automated exploitation
Scope
- Scope UnchangedImpact is limited to the vulnerable component itself
Impact if exploited
- Confidentiality LowSome restricted information is disclosed, but limited in scope
- Integrity NoneNo integrity impact
- Availability NoneNo availability impact
Weaknesses
ATT&CK techniques
Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.
Sources
References in the record
- access.redhat.com/errata/RHSA-2026:42922
- access.redhat.com/errata/RHSA-2026:55855
- access.redhat.com/security/cve/CVE-2026-59842
And 1 more reference. See all after sign-in
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