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Fencer Vulns
medium 6.4

CVE-2023-26555 json

praecis_parse in ntpd/refclock_palisade.c in NTP 4.2.8p15 has an out-of-bounds write.

published 2023-04-11 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-30352

cvss
6.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 44%
public exploits
0
none known

Summary

praecis_parse in ntpd/refclock_palisade.c in NTP 4.2.8p15 has an out-of-bounds write. Any attack method would be complex, e.g., with a manipulated GPS receiver.

Patch / fix

  • ntp SLES for SAP 12 SP5, SLES 12 SP5 4.2.8p17-103.1
  • ntp SLE Module for Legacy 15 SP5, SLE Module for Legacy 15 SP4, openSUSE Leap 15.5 +1 more 4.2.8p17-150000.4.25.1

suse advisories SUSE-SU-2023:2609-1SUSE-SU-2023:2608-1

  • ntp openSUSE Tumbleweed 4.2.8p17-1.1

opensuse advisories openSUSE-SU-2024:12997-1

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-2023-26555 updated cvss 5.1

ntp: an out-of-bounds write may lead to a DoS

  • Red Hat Enterprise Linux 6 ntp, ntpdate, ntp-perl
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 7 ntp, sntp, ntpdate, ntp-perl
    affected: no fix available “Fix deferred”

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

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
20 mo ago

Exploit prediction

0.52% chance of exploitation in the next 30 days, higher than 44% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 6.4 CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 6.4 CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA 3.1 6.4 CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Classification

Weakness

References

Sources

Fencer Vulns 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.