CVE-2023-26555

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.

Published: 2023-04-11 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-26555 is rated Low Risk (39/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.52%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-26555

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.94% 0.52% -0.42%
2 2026-05-22 0.76% 0.94% +0.18%
3 2026-04-29 — 0.76% —

Full EPSS history (16 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-26555

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.4 3.1 MEDIUM
CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:P)
Hands-on access—USB, keyboard, opening the case—not something you do purely over the wire.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 0.5 5.9 [email protected]
6.4 3.1 MEDIUM
CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:P)
Hands-on access—USB, keyboard, opening the case—not something you do purely over the wire.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 0.5 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2023-26555

OS Trackers for CVE-2023-26555

vendor priority summary link
debian not yet assigned CVE-2023-26555 not yet assigned priority: Debian including 1 source packages (ntp), 1 status rows across 1 suites (bullseye): open 1. https://security-tracker.debian.org/tracker/CVE-2023-26555
gentoo normal CVE-2023-26555: 1 GLSA(s) (202507-05), 1 atom(s) (net-misc/ntp); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2023-26555
redhat low — https://access.redhat.com/security/cve/CVE-2023-26555
suse medium — https://www.suse.com/security/cve/CVE-2023-26555/
ubuntu medium CVE-2023-26555 medium priority: Ubuntu including 1 source packages (ntp), 13 status rows across 13 suites (bionic, focal, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 7, needs-triage 6. https://ubuntu.com/security/CVE-2023-26555

Affected software / configurations for CVE-2023-26555

Vendor Product Version Raw CPE
ntp ntp 4.2.8 cpe:2.3:a:ntp:ntp:4.2.8:p15:*:*:*:*:*:*

References for CVE-2023-26555

cvelogic Threat Intelligence