mstolfp in libntp/mstolfp.c in NTP 4.2.8p15 has an out-of-bounds write in the cp<cpdec…
Priority LOW 26CWE-787Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- Low · Low · Low
- Fix status
- Will not fix Red Hat: no fix planned
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat.
Summary
mstolfp in libntp/mstolfp.c in NTP 4.2.8p15 has an out-of-bounds write in the cp<cpdec while loop. An adversary may be able to attack a client ntpq process, but cannot attack ntpd.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00665 52nd percentileScored 2026-11-07
Fix Will not fix Red Hat: no fix planned
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:ntp:ntp:4.2.8:p15:*:*:*:*:*:* | 4.2.8 p15 | Vulnerable | NTP Project |
- cpe:2.3:a:ntp:ntp:4.2.8:p15:*:*:*:*:*:* Versions 4.2.8 p15 Vulnerable ·NTP Project
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Will not fix |
Timeline
- 2026-10-02 Threatist record created from CVE-2023-26551
- 2026-10-03 Alias added: GHSA-536x-rjq6-h9w6
- 2026-10-04 EPSS moved to the 50th–90th percentile
References
More NTP Project Ntp vulnerabilities
- TI-2015-06541 Crypto-NAK packets in ntpd in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows… CVSS 3.1CRITICAL 9.8
- TI-2014-07543 Multiple stack-based buffer overflows in ntpd in NTP before 4.2.8 allow remote attackers… CVSS 2.0HIGH 7.5
- TI-2013-04524 The monlist feature in ntp_request.c in ntpd in NTP before 4.2.7p26 allows remote… CVSS 2.0MEDIUM 5.0
- TI-2016-06333 The read_mru_list function in NTP before 4.2.8p9 allows remote attackers to cause a… CVSS 3.1HIGH 7.5
- TI-2018-08842 Stack-based buffer overflow in ntpq and ntpdc of NTP version 4.2.8p11 allows an attacker… CVSS 3.0CRITICAL 9.8
- TI-2016-04280 ntpd in NTP before 4.2.8p8 allows remote attackers to cause a denial of service (daemon… CVSS 3.1HIGH 7.5
Sources
- CVE-2023-26551 · CVE Program
- CVE-2023-26551 · NVD
- FIRST EPSS
- GHSA-536x-rjq6-h9w6 · GitHub Advisory Database · CC BY 4.0
- CVE-2023-26551 · Red Hat security data · CC BY 4.0
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