p PatchFirst

CVE-2026-87865

CVE-2026-87865 · knownhost callback mismatches key as missing

This page contains facts from public vulnerability sources. Check the original advisory before updating.

When libcurl uses libssh2 with a hashed `known_hosts` file, an unrelated initial entry can cause host key validation to report a key *mismatch* as a *missing* key to the `CURLOPT_SSH_KEYFUNCTION` callback.

EPSS 0.3% · Fix available

Published
Updated

Stack: system

Affected products and versions

  • curl

    Versions
    • ≥ 8.22.0, ≤ 8.22.0: Affected (semver)
    • ≥ 8.21.0, ≤ 8.21.0: Affected (semver)
    • ≥ 8.20.0, ≤ 8.20.0: Affected (semver)
    • ≥ 8.19.0, ≤ 8.19.0: Affected (semver)
    • ≥ 8.18.0, ≤ 8.18.0: Affected (semver)
    • ≥ 8.17.0, ≤ 8.17.0: Affected (semver)
    • ≥ 8.16.0, ≤ 8.16.0: Affected (semver)
    • ≥ 8.15.0, ≤ 8.15.0: Affected (semver)
    • ≥ 8.14.1, ≤ 8.14.1: Affected (semver)
    • ≥ 8.14.0, ≤ 8.14.0: Affected (semver)
    • ≥ 8.13.0, ≤ 8.13.0: Affected (semver)
    • ≥ 8.12.1, ≤ 8.12.1: Affected (semver)
    • ≥ 8.12.0, ≤ 8.12.0: Affected (semver)
    • ≥ 8.11.1, ≤ 8.11.1: Affected (semver)
    • ≥ 8.11.0, ≤ 8.11.0: Affected (semver)
    • ≥ 8.10.1, ≤ 8.10.1: Affected (semver)
    • ≥ 8.10.0, ≤ 8.10.0: Affected (semver)
    • ≥ 8.9.1, ≤ 8.9.1: Affected (semver)
    • ≥ 8.9.0, ≤ 8.9.0: Affected (semver)
    • ≥ 8.8.0, ≤ 8.8.0: Affected (semver)
    • ≥ 8.7.1, ≤ 8.7.1: Affected (semver)
    • ≥ 8.7.0, ≤ 8.7.0: Affected (semver)
    • ≥ 8.6.0, ≤ 8.6.0: Affected (semver)
    • ≥ 8.5.0, ≤ 8.5.0: Affected (semver)
    • ≥ 8.4.0, ≤ 8.4.0: Affected (semver)
    • ≥ 8.3.0, ≤ 8.3.0: Affected (semver)
    • ≥ 8.2.1, ≤ 8.2.1: Affected (semver)
    • ≥ 8.2.0, ≤ 8.2.0: Affected (semver)
    • ≥ 8.1.2, ≤ 8.1.2: Affected (semver)
    • ≥ 8.1.1, ≤ 8.1.1: Affected (semver)
    • ≥ 8.1.0, ≤ 8.1.0: Affected (semver)
    • ≥ 8.0.1, ≤ 8.0.1: Affected (semver)
    • ≥ 8.0.0, ≤ 8.0.0: Affected (semver)
    • ≥ 7.88.1, ≤ 7.88.1: Affected (semver)
    • ≥ 7.88.0, ≤ 7.88.0: Affected (semver)
    • ≥ 7.87.0, ≤ 7.87.0: Affected (semver)
    • ≥ 7.86.0, ≤ 7.86.0: Affected (semver)
    • ≥ 7.85.0, ≤ 7.85.0: Affected (semver)
    • ≥ 7.84.0, ≤ 7.84.0: Affected (semver)
    • ≥ 7.83.1, ≤ 7.83.1: Affected (semver)
    • ≥ 7.83.0, ≤ 7.83.0: Affected (semver)
    • ≥ 7.82.0, ≤ 7.82.0: Affected (semver)
    • ≥ 7.81.0, ≤ 7.81.0: Affected (semver)
    • ≥ 7.80.0, ≤ 7.80.0: Affected (semver)
    • ≥ 7.79.1, ≤ 7.79.1: Affected (semver)
    • ≥ 7.79.0, ≤ 7.79.0: Affected (semver)
    • ≥ 7.78.0, ≤ 7.78.0: Affected (semver)
    • ≥ 7.77.0, ≤ 7.77.0: Affected (semver)
    • ≥ 7.76.1, ≤ 7.76.1: Affected (semver)
    • ≥ 7.76.0, ≤ 7.76.0: Affected (semver)
    • ≥ 7.75.0, ≤ 7.75.0: Affected (semver)
    • ≥ 7.74.0, ≤ 7.74.0: Affected (semver)
    • ≥ 7.73.0, ≤ 7.73.0: Affected (semver)
    • ≥ 7.72.0, ≤ 7.72.0: Affected (semver)
    • ≥ 7.71.1, ≤ 7.71.1: Affected (semver)
    • ≥ 7.71.0, ≤ 7.71.0: Affected (semver)
    • ≥ 7.70.0, ≤ 7.70.0: Affected (semver)
    • ≥ 7.69.1, ≤ 7.69.1: Affected (semver)

    No fix published

  • curl Debian:12

    Versions
    • 7.88.1-10
    • 7.88.1-10+deb12u1
    • 7.88.1-10+deb12u11
    • 7.88.1-10+deb12u12
    • 7.88.1-10+deb12u13
    • 7.88.1-10+deb12u14
    • 7.88.1-10+deb12u15
    • 7.88.1-10+deb12u1~bpo11+1
    • 7.88.1-10+deb12u2
    • 7.88.1-10+deb12u3
    • 7.88.1-10+deb12u3~bpo11+1
    • 7.88.1-10+deb12u4
    • 7.88.1-10+deb12u5
    • 7.88.1-10+deb12u5~bpo11+1
    • 7.88.1-10+deb12u6
    • 7.88.1-10+deb12u6~bpo11+1
    • 7.88.1-10+deb12u7
    • 7.88.1-10+deb12u8
    • 7.88.1-10+deb12u9
    • 7.88.1-11
    • 8.0.1-1~exp1
    • 8.10.0-1
    • 8.10.0-2
    • 8.10.1-1
    • 8.10.1-1~bpo12+1
    • 8.10.1-2
    • 8.11.0-1
    • 8.11.1-1
    • 8.11.1-1~bpo12+1
    • 8.12.0+git20250209.89ed161+ds-1
    • 8.12.0+git20250209.89ed161+ds-1~bpo12+1
    • 8.12.1-1
    • 8.12.1-2
    • 8.12.1-2~bpo12+1
    • 8.12.1-3
    • 8.12.1-3~bpo12+1
    • 8.13.0-1
    • 8.13.0-1+exp1
    • 8.13.0-2
    • 8.13.0-2+exp1
    • 8.13.0-3
    • 8.13.0-4
    • 8.13.0-4+exp1
    • 8.13.0-5
    • 8.13.0-5+exp1
    • 8.13.0-5~bpo12+1
    • 8.13.0~rc-1~exp1
    • 8.13.0~rc-1~exp2
    • 8.13.0~rc2-1
    • 8.13.0~rc2-2
    • 8.13.0~rc3-1
    • 8.13.0~rc3-1+exp1
    • 8.14.0-1
    • 8.14.0-1+exp1
    • 8.14.0~rc1-1+exp1
    • 8.14.0~rc2-1+exp1
    • 8.14.0~rc3-1+exp1
    • 8.14.1-1
    • 8.14.1-1~bpo12+1
    • 8.14.1-2
    • 8.14.1-2+exp1
    • 8.14.1-2~bpo12+1
    • 8.15.0-1
    • 8.15.0-1~bpo13+1
    • 8.15.0-1~exp1
    • 8.15.0~rc1-1exp1
    • 8.15.0~rc2-1~exp1
    • 8.15.0~rc3-1~exp1
    • 8.16.0-1
    • 8.16.0-1+exp1
    • 8.16.0-1~bpo13+1
    • 8.16.0-2
    • 8.16.0-3
    • 8.16.0-4
    • 8.16.0-4~bpo13+1
    • 8.16.0~rc1-1~exp1
    • 8.16.0~rc2-1
    • 8.16.0~rc2-2
    • 8.16.0~rc3-1
    • 8.17.0-1
    • 8.17.0-2
    • 8.17.0-3
    • 8.17.0~rc1-1~exp1
    • 8.17.0~rc2-1
    • 8.17.0~rc3-1
    • 8.18.0-1
    • 8.18.0-1~bpo13+1
    • 8.18.0-2
    • 8.18.0~rc1-1+exp1
    • 8.18.0~rc2-1
    • 8.18.0~rc3-1
    • 8.19.0-1
    • 8.19.0-1+exp1
    • 8.19.0-1~bpo13+1
    • 8.19.0-2
    • 8.19.0-3
    • 8.19.0-3+exp1
    • 8.19.0-3+exp2
    • 8.19.0~rc1-1~exp1
    • 8.19.0~rc2-1
    • 8.19.0~rc2-2
    • 8.19.0~rc3-1
    • 8.2.1-1
    • 8.2.1-2
    • 8.2.1-2~bpo12+1
    • 8.20.0-1
    • 8.20.0-1+exp
    • 8.20.0-2
    • 8.20.0-2+exp1
    • 8.20.0-2~bpo13+1
    • 8.20.0-3
    • 8.20.0-4
    • 8.20.0-5
    • 8.20.0-5~bpo13+1
    • 8.20.0~rc1-1+exp1
    • 8.20.0~rc1-1+exp2
    • 8.20.0~rc1-1+exp3
    • 8.20.0~rc2-1
    • 8.20.0~rc2-1+exp1
    • 8.20.0~rc3-1
    • 8.20.0~rc3-1+exp1
    • 8.21.0-1
    • 8.21.0-1+exp1
    • 8.21.0-2
    • 8.21.0-2+exp1
    • 8.21.0-2~bpo13+1
    • 8.21.0~rc1-1+exp1
    • 8.21.0~rc2-1
    • 8.21.0~rc2-1+exp1
    • 8.21.0~rc3-1
    • 8.21.0~rc3-1+exp1
    • 8.22.0-1
    • 8.22.0-1+exp1
    • 8.22.0~rc2-1
    • 8.22.0~rc2-2
    • 8.22.0~rc3-1
    • 8.22.0~rc3-1+exp1
    • 8.23.0-1
    • 8.23.0~rc1-1
    • 8.23.0~rc1-2
    • 8.23.0~rc2-1
    • 8.23.0~rc2-1+exp1
    • 8.23.0~rc3-1
    • 8.23.0~rc3-1+exp1
    • 8.3.0-1
    • 8.3.0-2
    • 8.3.0-2~bpo12+1
    • 8.3.0-2~exp1
    • 8.3.0-3
    • 8.4.0-1
    • 8.4.0-2
    • 8.4.0-2~bpo12+1
    • 8.5.0-1
    • 8.5.0-1+exp1
    • 8.5.0-2
    • 8.5.0-2+exp1
    • 8.5.0-2~bpo12+1
    • 8.6.0-1
    • 8.6.0-1.1
    • 8.6.0-2
    • 8.6.0-3
    • 8.6.0-3.1
    • 8.6.0-3.1~exp1
    • 8.6.0-3.1~exp2
    • 8.6.0-3.2
    • 8.6.0-4
    • 8.7.1-1
    • 8.7.1-1+exp1
    • 8.7.1-2
    • 8.7.1-3
    • 8.7.1-4
    • 8.7.1-5
    • 8.7.1-5+exp1
    • 8.7.1-5~bpo12+1
    • 8.8.0-1
    • 8.8.0-1+exp1
    • 8.8.0-1+exp2
    • 8.8.0-1~bpo12+1
    • 8.8.0-2
    • 8.8.0-3
    • 8.8.0-4
    • 8.9.0-1
    • 8.9.0-2
    • 8.9.0-3
    • 8.9.1-1
    • 8.9.1-2
    • 8.9.1-2~bpo12+1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • curl Debian:13

    Versions
    • 8.14.1-2
    • 8.14.1-2+deb13u1
    • 8.14.1-2+deb13u2
    • 8.14.1-2+deb13u2~bpo13+1
    • 8.14.1-2+deb13u3
    • 8.14.1-2+deb13u4
    • 8.14.1-2+deb13u5
    • 8.14.1-2+deb13u7
    • 8.14.1-2+exp1
    • 8.15.0-1
    • 8.15.0-1~bpo13+1
    • 8.15.0-1~exp1
    • 8.15.0~rc1-1exp1
    • 8.15.0~rc2-1~exp1
    • 8.15.0~rc3-1~exp1
    • 8.16.0-1
    • 8.16.0-1+exp1
    • 8.16.0-1~bpo13+1
    • 8.16.0-2
    • 8.16.0-3
    • 8.16.0-4
    • 8.16.0-4~bpo13+1
    • 8.16.0~rc1-1~exp1
    • 8.16.0~rc2-1
    • 8.16.0~rc2-2
    • 8.16.0~rc3-1
    • 8.17.0-1
    • 8.17.0-2
    • 8.17.0-3
    • 8.17.0~rc1-1~exp1
    • 8.17.0~rc2-1
    • 8.17.0~rc3-1
    • 8.18.0-1
    • 8.18.0-1~bpo13+1
    • 8.18.0-2
    • 8.18.0~rc1-1+exp1
    • 8.18.0~rc2-1
    • 8.18.0~rc3-1
    • 8.19.0-1
    • 8.19.0-1+exp1
    • 8.19.0-1~bpo13+1
    • 8.19.0-2
    • 8.19.0-3
    • 8.19.0-3+exp1
    • 8.19.0-3+exp2
    • 8.19.0~rc1-1~exp1
    • 8.19.0~rc2-1
    • 8.19.0~rc2-2
    • 8.19.0~rc3-1
    • 8.20.0-1
    • 8.20.0-1+exp
    • 8.20.0-2
    • 8.20.0-2+exp1
    • 8.20.0-2~bpo13+1
    • 8.20.0-3
    • 8.20.0-4
    • 8.20.0-5
    • 8.20.0-5~bpo13+1
    • 8.20.0~rc1-1+exp1
    • 8.20.0~rc1-1+exp2
    • 8.20.0~rc1-1+exp3
    • 8.20.0~rc2-1
    • 8.20.0~rc2-1+exp1
    • 8.20.0~rc3-1
    • 8.20.0~rc3-1+exp1
    • 8.21.0-1
    • 8.21.0-1+exp1
    • 8.21.0-2
    • 8.21.0-2+exp1
    • 8.21.0-2~bpo13+1
    • 8.21.0~rc1-1+exp1
    • 8.21.0~rc2-1
    • 8.21.0~rc2-1+exp1
    • 8.21.0~rc3-1
    • 8.21.0~rc3-1+exp1
    • 8.22.0-1
    • 8.22.0-1+exp1
    • 8.22.0~rc2-1
    • 8.22.0~rc2-2
    • 8.22.0~rc3-1
    • 8.22.0~rc3-1+exp1
    • 8.23.0-1
    • 8.23.0~rc1-1
    • 8.23.0~rc1-2
    • 8.23.0~rc2-1
    • 8.23.0~rc2-1+exp1
    • 8.23.0~rc3-1
    • 8.23.0~rc3-1+exp1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • curl Debian:14

    Versions
    • 8.14.1-2
    • 8.14.1-2+exp1
    • 8.15.0-1
    • 8.15.0-1~bpo13+1
    • 8.15.0-1~exp1
    • 8.15.0~rc1-1exp1
    • 8.15.0~rc2-1~exp1
    • 8.15.0~rc3-1~exp1
    • 8.16.0-1
    • 8.16.0-1+exp1
    • 8.16.0-1~bpo13+1
    • 8.16.0-2
    • 8.16.0-3
    • 8.16.0-4
    • 8.16.0-4~bpo13+1
    • 8.16.0~rc1-1~exp1
    • 8.16.0~rc2-1
    • 8.16.0~rc2-2
    • 8.16.0~rc3-1
    • 8.17.0-1
    • 8.17.0-2
    • 8.17.0-3
    • 8.17.0~rc1-1~exp1
    • 8.17.0~rc2-1
    • 8.17.0~rc3-1
    • 8.18.0-1
    • 8.18.0-1~bpo13+1
    • 8.18.0-2
    • 8.18.0~rc1-1+exp1
    • 8.18.0~rc2-1
    • 8.18.0~rc3-1
    • 8.19.0-1
    • 8.19.0-1+exp1
    • 8.19.0-1~bpo13+1
    • 8.19.0-2
    • 8.19.0-3
    • 8.19.0-3+exp1
    • 8.19.0-3+exp2
    • 8.19.0~rc1-1~exp1
    • 8.19.0~rc2-1
    • 8.19.0~rc2-2
    • 8.19.0~rc3-1
    • 8.20.0-1
    • 8.20.0-1+exp
    • 8.20.0-2
    • 8.20.0-2+exp1
    • 8.20.0-2~bpo13+1
    • 8.20.0-3
    • 8.20.0-4
    • 8.20.0-5
    • 8.20.0-5~bpo13+1
    • 8.20.0~rc1-1+exp1
    • 8.20.0~rc1-1+exp2
    • 8.20.0~rc1-1+exp3
    • 8.20.0~rc2-1
    • 8.20.0~rc2-1+exp1
    • 8.20.0~rc3-1
    • 8.20.0~rc3-1+exp1
    • 8.21.0-1
    • 8.21.0-1+exp1
    • 8.21.0-2
    • 8.21.0-2+exp1
    • 8.21.0-2~bpo13+1
    • 8.21.0~rc1-1+exp1
    • 8.21.0~rc2-1
    • 8.21.0~rc2-1+exp1
    • 8.21.0~rc3-1
    • 8.21.0~rc3-1+exp1
    • 8.22.0-1
    • 8.22.0-1+exp1
    • 8.22.0~rc2-1
    • 8.22.0~rc2-2
    • 8.22.0~rc3-1
    • 8.22.0~rc3-1+exp1
    • 8.23.0-1
    • 8.23.0~rc1-1
    • 8.23.0~rc1-2
    • 8.23.0~rc2-1
    • 8.23.0~rc2-1+exp1
    • 8.23.0~rc3-1
    • 8.23.0~rc3-1+exp1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • curl Ubuntu:26.10

    Versions
    • 8.18.0-1ubuntu2
    • 8.20.0-2ubuntu1
    • 8.20.0-2ubuntu3
    • 8.20.0-2ubuntu10
    • 8.20.0-2ubuntu11
    Affected ranges
    • ECOSYSTEM: < 8.20.0-2ubuntu11.1

    Update to 8.20.0-2ubuntu11.1

  • curl Ubuntu:26.04:LTS

    Versions
    • 8.14.1-2ubuntu1
    • 8.17.0-1ubuntu1
    • 8.18.0-1ubuntu1
    • 8.18.0-1ubuntu2
    • 8.18.0-1ubuntu2.1
    • 8.18.0-1ubuntu2.2
    • 8.18.0-1ubuntu2.3
    • 8.18.0-1ubuntu2.4
    • 8.18.0-1ubuntu2.5
    • 8.18.0-1ubuntu2.7
    Affected ranges
    • ECOSYSTEM: < 8.18.0-1ubuntu2.8

    Update to 8.18.0-1ubuntu2.8

Original sources

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