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Vulnerabilities

Vulnerability · CVE-2025-8277

A flaw was found in libssh's handling of key exchange (KEX) processes when a client repeatedly sends incorrect KEX guesses.

Published Sep 9, 2025 · catalog updated Sep 1, 2026 · Red Hat Red Hat Enterprise Linux 9

Check this week

CVE-2025-8277 is not in CISA KEV. FIRST estimates a 43.00% chance of exploitation in the next 30 days. Check whether you run Red Hat Red Hat Enterprise Linux 9.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Low3.1
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
43.00%
Remediation
Advisory link
Affected products
vendor Red Hat Red Hat Enterprise Linux 9 patch: 0:0.10.4-18.el9

A flaw was found in libssh's handling of key exchange (KEX) processes when a client repeatedly sends incorrect KEX guesses. The library fails to free memory during these rekey operations, which can gradually exhaust system memory. This issue can lead to crashes on the client side, particularly when using libgcrypt, which impacts application stability and availability.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor Red Hat Red Hat Enterprise Linux 9 patch: 0:0.10.4-18.el9patch: 0:0.10.4-18.el9

How to fix CVE-2025-8277

  • Recommended remediation

    A patch or advisory reference is linked. Open the original publisher for availability by product version.

  • Official advisories

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

CVE-2025-8277 is not in CISA KEV. FIRST estimates a 43.00% chance of exploitation in the next 30 days. Check whether you run Red Hat Red Hat Enterprise Linux 9.

Which versions are affected?

Compare what you have installed with Red Hat Red Hat Enterprise Linux 9 patch: 0:0.10.4-18.el9 patch: 0:0.10.4-18.el9. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 43.00%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Sep 9, 2025 · EUVD

    Detected

    A flaw was found in libssh's handling of key exchange (KEX) processes when a client repeatedly sends incorrect KEX guesses. The library fails to free memory during these rekey operations, which can gradually exhaust system memory. This issue can lead to crashes on the client side, particularly when using libgcrypt, which impacts application stability and availability.

  2. Sep 1, 2026 · EUVD

    Updated

    A flaw was found in libssh's handling of key exchange (KEX) processes when a client repeatedly sends incorrect KEX guesses. The library fails to free memory during these rekey operations, which can gradually exhaust system memory. This issue can lead to crashes on the client side, particularly when using libgcrypt, which impacts application stability and availability.

Sources

  • EUVDVulnerability recordEUVD-2025-27246

    A flaw was found in libssh's handling of key exchange (KEX) processes when a client repeatedly sends incorrect KEX guesses. The library fails to free memory during these rekey operations, which can gradually exhaust system memory. This issue can lead to crashes on the client side

    euvd.enisa.europa.eu

References

Freshness

Last verified in this catalog Sep 1, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.