CVE-2023-1555 | Missing Authorization in GitLab

An issue has been discovered in GitLab affecting all versions starting from 15.2 before 16.1.5, all versions starting from 16.2 before 16.2.5, all versions starting from 16.3 before 16.3.1. A namespace-level banned user can access the API.

Published: 2023-09-01 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-1555 is rated Low Risk (21.7/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.39%). 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-2023-1555

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 0.06% 0.39% +0.33%
2 2026-03-04 0.02% 0.06% +0.05%
3 2026-03-01 — 0.02% —

Full EPSS history (19 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-1555

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
2.7 3.1 LOW
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 1.2 1.4 [email protected]
4.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 1.4 [email protected]

Weakness enumeration for CVE-2023-1555

OS Trackers for CVE-2023-1555

vendor priority summary link
debian not yet assigned CVE-2023-1555 not yet assigned priority: Debian including 1 source packages (gitlab), 1 status rows across 1 suites (sid): resolved 1. https://security-tracker.debian.org/tracker/CVE-2023-1555
ubuntu medium CVE-2023-1555 medium priority: Ubuntu including 1 source packages (gitlab), 9 status rows across 9 suites (bionic, focal, jammy, lunar, mantic, noble, trusty, upstream, xenial): DNE 5, ignored 3, needs-triage 1. https://ubuntu.com/security/CVE-2023-1555

Affected software / configurations for CVE-2023-1555

Vendor Product Version Raw CPE
gitlab gitlab >= 15.2.0, < 16.1.5 cpe:2.3:a:gitlab:gitlab:*:*:*:*:community:*:*:*
gitlab gitlab >= 15.2.0, < 16.1.5 cpe:2.3:a:gitlab:gitlab:*:*:*:*:enterprise:*:*:*
gitlab gitlab >= 16.2, < 16.2.5 cpe:2.3:a:gitlab:gitlab:*:*:*:*:community:*:*:*
gitlab gitlab >= 16.2, < 16.2.5 cpe:2.3:a:gitlab:gitlab:*:*:*:*:enterprise:*:*:*
gitlab gitlab 16.3.0 cpe:2.3:a:gitlab:gitlab:16.3.0:*:*:*:community:*:*:*
gitlab gitlab 16.3.0 cpe:2.3:a:gitlab:gitlab:16.3.0:*:*:*:enterprise:*:*:*

References for CVE-2023-1555

cvelogic Threat Intelligence