CVE-2023-26555
praecis_parse in ntpd/refclock_palisade.c in NTP 4.2.8p15 has an out-of-bounds write.
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.
Attack profile
How easy it is to exploit
- Attack vector
- Physical
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
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.
- Record
CVE-2023-26555- CVSS 3.1
- 6.4 Medium
CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-787
- Updated
- 2026-11-02
CVE List
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.
- Record
CVE-2023-26555- CVSS 3.1
- 6.4 Medium
CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-787
- Updated
- 2026-11-02
EUVDEUVD-2023-30352
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.
- Record
EUVD-2023-30352- CVSS 3.1
- 6.4 Medium
CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-3vvp-9ghf-fqvw
praecis_parse in ntpd/refclock_palisade.c in NTP 4.2.8p15 has an out-of-bounds write.
praecis_parse in ntpd/refclock_palisade.c in NTP 4.2.8p15 has an out-of-bounds write.
- Record
GHSA-3vvp-9ghf-fqvw- CVSS 3.1
- 6.4 Medium
CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-787
- Updated
- 2026-11-02
OSV
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.
- Record
CVE-2023-26555- CVSS 3.1
- 6.4 Medium
CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVDEBIAN-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.
- Record
DEBIAN-CVE-2023-26555- CVSS 3.1
- 6.4 Medium
CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
Show 5 moreShow less
OSVOESA-2023-1292
ntp security update
NTP is a protocol designed to synchronize the clocks of computers over a network, NTP version 4, a significant revision of the previous NTP standard, is the current development version. It is formalized by RFCs released by the IETF.
Security Fix(es):
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.(CVE-2023-26555)
- Record
OESA-2023-1292- CVSS 3.1
- 6.4 Medium
CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVUBUNTU-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.
- Record
UBUNTU-CVE-2023-26555- CVSS 3.1
- 6.4 Medium
CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVopenSUSE-SU-2024:12997-1 No score
ntp-4.2.8p17-1.1 on GA media
These are all security issues fixed in the ntp-4.2.8p17-1.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2024:12997-1- Updated
- 2026-11-02
OSVSUSE-SU-2023:2608-1 No score
Security update for ntp
This update for ntp fixes the following issues:
- CVE-2023-26555: Fixed assertion failure on malformed RT-11 dates (bsc#1210390).
- Record
SUSE-SU-2023:2608-1- Updated
- 2026-11-02
OSVSUSE-SU-2023:2609-1 No score
Security update for ntp
This update for ntp fixes the following issues:
ntp was updated to 4.2.8p17:
- Fix some regressions of 4.2.8p16
Update to 4.2.8p16:
-
[Sec 3808] Assertion failure in ntpq on malformed RT-11 date
-
[Sec 3807], bsc#1210390, CVE-2023-26555: praecis_parse() in the Palisade refclock driver has a hypothetical input buffer overflow.
-
[Sec 3767] An OOB KoD RATE value triggers an assertion when debug is enabled.
-
Multiple bug fixes and improvements. For details, see /usr/share/doc/packages/ntp/ChangeLog
http://www.ntp.org/support/securitynotice/4_2_8-series-changelog/
- CVE-2023-26555: Fixed assertion failure on malformed RT-11 dates (bsc#1210390).
- Record
SUSE-SU-2023:2609-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
ntpDebian:11 |
All versions, plus listed versions 1:4.2.8p15+dfsg-11:4.2.8p15+dfsg-2-hurd.11:4.2.8p15+dfsg-2~1.2.1+dfsg1-7+hurd.11:4.2.8p15+dfsg-2~1.2.1+dfsg1-8+hurd.11:4.2.8p15+dfsg-2~1.2.2+dfsg1-2+hurd.11:4.2.8p15+dfsg-2~hurd.1 |
None known |
ntpopenEuler:20.03-LTS-SP1 |
before 4.2.8p14-8.oe1 | 4.2.8p14-8.oe1 |
ntpopenEuler:20.03-LTS-SP3 |
before 4.2.8p14-8.oe1 | 4.2.8p14-8.oe1 |
ntpopenEuler:22.03-LTS |
before 4.2.8p15-10.oe2203sp1 | 4.2.8p15-10.oe2203sp1 |
ntpopenEuler:22.03-LTS-SP1 |
before 4.2.8p15-10.oe2203sp1 | 4.2.8p15-10.oe2203sp1 |
ntpSUSE:Linux Enterprise Module for Legacy 15 SP4 |
before 4.2.8p17-150000.4.25.1 | 4.2.8p17-150000.4.25.1 |
ntpSUSE:Linux Enterprise Module for Legacy 15 SP5 |
before 4.2.8p17-150000.4.25.1 | 4.2.8p17-150000.4.25.1 |
ntpopenSUSE:Leap 15.4 |
before 4.2.8p17-150000.4.25.1 | 4.2.8p17-150000.4.25.1 |
ntpopenSUSE:Leap 15.5 |
before 4.2.8p17-150000.4.25.1 | 4.2.8p17-150000.4.25.1 |
ntpSUSE:Linux Enterprise Server 12 SP5 |
before 4.2.8p17-103.1 | 4.2.8p17-103.1 |
Show 7 moreShow less
| Package | Affected | Fixed |
|---|---|---|
ntpSUSE:Linux Enterprise Server for SAP Applications 12 SP5 |
before 4.2.8p17-103.1 | 4.2.8p17-103.1 |
ntpUbuntu:Pro:14.04:LTS |
All versions, plus listed versions 1:4.2.6.p5+dfsg-3ubuntu21:4.2.6.p5+dfsg-3ubuntu2.14.04.11:4.2.6.p5+dfsg-3ubuntu2.14.04.21:4.2.6.p5+dfsg-3ubuntu2.14.04.31:4.2.6.p5+dfsg-3ubuntu2.14.04.5 Show 8 moreShow less1:4.2.6.p5+dfsg-3ubuntu2.14.04.61:4.2.6.p5+dfsg-3ubuntu2.14.04.71:4.2.6.p5+dfsg-3ubuntu2.14.04.81:4.2.6.p5+dfsg-3ubuntu2.14.04.101:4.2.6.p5+dfsg-3ubuntu2.14.04.111:4.2.6.p5+dfsg-3ubuntu2.14.04.121:4.2.6.p5+dfsg-3ubuntu2.14.04.131:4.2.6.p5+dfsg-3ubuntu2.14.04.13+esm1 |
None known |
ntpUbuntu:16.04:LTS |
All versions, plus listed versions 1:4.2.6.p5+dfsg-3ubuntu81:4.2.6.p5+dfsg-3ubuntu8.11:4.2.6.p5+dfsg-3ubuntu91:4.2.8p4+dfsg-3ubuntu11:4.2.8p4+dfsg-3ubuntu2 Show 13 moreShow less1:4.2.8p4+dfsg-3ubuntu31:4.2.8p4+dfsg-3ubuntu41:4.2.8p4+dfsg-3ubuntu51:4.2.8p4+dfsg-3ubuntu5.11:4.2.8p4+dfsg-3ubuntu5.21:4.2.8p4+dfsg-3ubuntu5.31:4.2.8p4+dfsg-3ubuntu5.41:4.2.8p4+dfsg-3ubuntu5.51:4.2.8p4+dfsg-3ubuntu5.61:4.2.8p4+dfsg-3ubuntu5.71:4.2.8p4+dfsg-3ubuntu5.81:4.2.8p4+dfsg-3ubuntu5.91:4.2.8p4+dfsg-3ubuntu5.10 |
None known |
ntpUbuntu:Pro:18.04:LTS |
All versions, plus listed versions 1:4.2.8p10+dfsg-5ubuntu31:4.2.8p10+dfsg-5ubuntu41:4.2.8p10+dfsg-5ubuntu51:4.2.8p10+dfsg-5ubuntu61:4.2.8p10+dfsg-5ubuntu7 Show 7 moreShow less1:4.2.8p10+dfsg-5ubuntu7.11:4.2.8p10+dfsg-5ubuntu7.1+esm11:4.2.8p10+dfsg-5ubuntu7.1+esm21:4.2.8p10+dfsg-5ubuntu7.21:4.2.8p10+dfsg-5ubuntu7.2+esm11:4.2.8p10+dfsg-5ubuntu7.31:4.2.8p10+dfsg-5ubuntu7.3+esm1 |
None known |
ntpUbuntu:Pro:20.04:LTS |
All versions, plus listed versions 1:4.2.8p12+dfsg-3ubuntu21:4.2.8p12+dfsg-3ubuntu31:4.2.8p12+dfsg-3ubuntu41:4.2.8p12+dfsg-3ubuntu4.20.04.11:4.2.8p12+dfsg-3ubuntu4.20.04.1+esm1 |
None known |
ntpUbuntu:22.04:LTS |
All versions, plus listed versions 1:4.2.8p12+dfsg-3ubuntu61:4.2.8p15+dfsg-1ubuntu11:4.2.8p15+dfsg-1ubuntu2 |
None known |
ntpopenSUSE:Tumbleweed |
before 4.2.8p17-1.1 | 4.2.8p17-1.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2023-26555 is a medium vulnerability (CVSS 6.4) in Ntp, published April 11, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.52%, the 44th percentile. Fixed in ntp 4.2.8p14-8.oe1.
References
github.com/spwpun/ntp-4.2.8p15-cves/blob/main/CVE-2023-26555
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IY2SVYH4MKPAXEYHCCXD3Z6VGINLSVHK
nvd.nist.gov/vuln/detail/CVE-2023-26555
Show 10 moreShow less
security-tracker.debian.org/tracker/CVE-2023-26555
openeuler.org/en/security/safety-bulletin/detail.html?id=openEuler-SA-2023-1292
suse.com/support/update/announcement/2023/suse-su-20232608-1
bugzilla.suse.com/1210390
ubuntu.com/security/CVE-2023-26555
cve.org/CVERecord?id=CVE-2023-26555