How severe is CVE-2023-26555?

CVE-2023-26555 has a CVSS 3.x base score of 6.4, rated medium severity. It is exploitable over physical access with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2023-26555 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (40th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-26555?

CVE-2023-26555 affects Ntp. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-26555?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2023-26555 published?

CVE-2023-26555 was published on 2023-04-11 and last updated on 2026-06-17.

CVE-2023-26555

CVE-2023-26555 is a medium-severity vulnerability in Ntp with a CVSS 3.x base score of 6.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.

Key facts

Severity: Medium (CVSS 3.x base score 6.4)
EPSS exploit prediction: 1% (40th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Ntp
Published: 2023-04-11
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is 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.
How severe is CVE-2023-26555?: CVE-2023-26555 has a CVSS 3.x base score of 6.4, rated medium severity. It is exploitable over physical access with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2023-26555 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (40th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-26555?: CVE-2023-26555 affects Ntp. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-26555?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-26555 published?: CVE-2023-26555 was published on 2023-04-11 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:ntp:ntp:4.2.8:p15:*:*:*:*:*:*

More vulnerabilities in Ntp

CVE-2018-12327 — Critical (CVSS 9.8): Stack-based buffer overflow in ntpq and ntpdc of NTP version 4.2.8p11 allows an attacker to achieve code execution or…
CVE-2018-7183 — Critical (CVSS 9.8): Buffer overflow in the decodearr function in ntpq in ntp 4.2.8p6 through 4.2.8p10 allows remote attackers to execute…
CVE-2015-7871 — Critical (CVSS 9.8): Crypto-NAK packets in ntpd in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows remote attackers to bypass…
CVE-2015-7853 — Critical (CVSS 9.8): The datalen parameter in the refclock driver in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows remote…
CVE-2015-7705 — Critical (CVSS 9.8): The rate limiting feature in NTP 4.x before 4.2.8p4 and 4.3.x before 4.3.77 allows remote attackers to have unspecified…
CVE-2015-7854 — High (CVSS 8.8): Buffer overflow in the password management functionality in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows…

All CVEs affecting Ntp →

Other CWE-787 (Out-of-bounds Write) vulnerabilities

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CVE-2025-24201 — Critical (CVSS 10.0): An out-of-bounds write issue was addressed with improved checks to prevent unauthorized actions. This issue is fixed in…
CVE-2024-42479 — Critical (CVSS 10.0): llama.cpp provides LLM inference in C/C++. The unsafe `data` pointer member in the `rpc_tensor` structure can cause…
CVE-2024-39791 — Critical (CVSS 10.0): Stack-based buffer overflow vulnerabilities affecting Vonets industrial wifi bridge relays and wifi bridge…

Browse all CWE-787 (Out-of-bounds Write) vulnerabilities →

Threat intelligence

Threat-intel indicators referencing this CVE:

197.248.207.139 (ipv4-addr)
135.129.128.247 (ipv4-addr)
119.201.59.224 (ipv4-addr)
125.212.244.35 (ipv4-addr)
202.29.220.126 (ipv4-addr)
93.42.227.251 (ipv4-addr)
82.209.191.11 (ipv4-addr)
119.204.60.250 (ipv4-addr)