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Fencer Intel
high 8.1

CVE-2019-13115 in the critical feed json

In libssh2 before 1.9.0, kex_method_diffie_hellman_group_exchange_sha256_key_exchange in kex.c has an integer overflow that could lead to a…

published 7y ago modified 4mo ago also EUVD-2019-4656

cvss
8.1
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
11.7%
EPSS 11.7% chance of exploitation in 30 days, percentile 96%
public exploits
0
none known

Summary

In libssh2 before 1.9.0, kex_method_diffie_hellman_group_exchange_sha256_key_exchange in kex.c has an integer overflow that could lead to an out-of-bounds read in the way packets are read from the server. A remote attacker who compromises a SSH server may be able to disclose sensitive information or cause a denial of service condition on the client system when a user connects to the server. This is related to an _libssh2_check_length mistake, and is different from the various issues fixed in 1.8.1, such as CVE-2019-3855.

Patch / fix

  • libssh2 libssh2 1.9.0
  • libssh2 Debian 14, Debian 13, Debian 12 1.9.0-1

debian advisories DEBIAN-CVE-2019-13115

  • libssh2 Ubuntu Pro 14.04 LTS 1.4.3-2ubuntu0.2+esm2
  • libssh2 Ubuntu Pro 16.04 LTS 1.5.0-2ubuntu0.1+esm1

ubuntu advisories UBUNTU-CVE-2019-13115

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • libssh2 Alpine 3.24, Alpine 3.23, Alpine 3.22 +13 more 1.9.0-r0

alpine advisories ALPINE-CVE-2019-13115

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Is CVE-2019-13115 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2019-13115 updated cvss 6.8

libssh2: integer overflow in kex_method_diffie_hellman_group_exchange_sha256_key_exchange in kex.c leads to out-of-bounds write

  • Red Hat Enterprise Linux 6 libssh2
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 7 libssh2 Red Hat Enterprise Linux 8 Advanced Virtualization libssh2
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux 8 libssh2
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

11.66% chance of exploitation in the next 30 days, higher than 96% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • blog.semmle.com https://blog.semmle.com/libssh2-integer-overflow/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 8.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
NVD 2.0 5.8 AV:N/AC:M/Au:N/C:P/I:N/A:P

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.