Security readout for executives and security teams
Plain-English summary
GitLab CE/EE package upload handling allowed authenticated users to place uploaded packages outside intended locations. The business risk is unauthorized file writes that could alter application data or disrupt service. Exposure is limited to listed GitLab CE/EE versions starting 12.8 and requires a logged-in attacker, but the network attack surface and low complexity make it high priority.
Executive priority
Patch or upgrade affected GitLab instances promptly, especially internet-facing or broadly accessible environments. This is not currently supported as actively exploited by the provided sources, but unauthorized file placement in a source-code platform creates meaningful integrity and availability risk.
Technical view
CVE-2020-26405 is a path traversal flaw in GitLab CE/EE package upload functionality. Affected versions are >=12.8 <13.3.9, >=13.4 <13.4.5, and >=13.5 <13.5.2. CVSS 3.1 is 7.1 with network access, low complexity, low privileges, no user interaction, high integrity impact, and low availability impact.
Likely exposure
Likely exposure exists where self-managed GitLab CE/EE runs affected versions and package upload features are reachable by authenticated users. The bundle does not identify affected CPEs, deployment defaults, or whether GitLab.com was impacted, so asset and version validation is necessary.
Exploitation context
The sources describe a reported path traversal issue, but the bundle does not cite CISA KEV listing or active exploitation. Treat exploitation as plausible for exposed affected instances because the attack is network-reachable, low complexity, and requires only low privileges.
Researcher notes
Evidence is limited to the CVE description, GitLab CVE metadata, GitLab issue reference, and HackerOne report reference. The bundle does not provide CWE, proof-of-concept details, exploit telemetry, or complete remediation notes. Avoid assuming unauthenticated exploitation or confidentiality impact.
Mitigation direction
- Upgrade GitLab CE/EE off the affected version ranges.
- Prioritize at least 13.3.9, 13.4.5, 13.5.2, or later unaffected releases.
- Review GitLab vendor guidance for any additional hardening or operational steps.
- Limit package upload access to trusted authenticated users until remediation completes.
Validation and detection
- Inventory all GitLab CE/EE instances and record exact versions.
- Confirm no instance runs >=12.8 <13.3.9, >=13.4 <13.4.5, or >=13.5 <13.5.2.
- Check whether package upload functionality is enabled and reachable by authenticated users.
- Review logs for unusual package uploads or unexpected file write behavior.
- Document remediation evidence for vulnerability management tracking.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
File access behavior lookup
The CVE wording references file access or upload behavior, so file telemetry and web shell review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2020-26405 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L2.84.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.1HighVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L
Source materials
- CVE List V5 sourceCVE List V5
- https://gitlab.com/gitlab-org/gitlab/-/issues/247371CVE reference · x_refsource_MISC
- https://hackerone.com/reports/835427CVE reference · x_refsource_MISC
- https://gitlab.com/gitlab-org/cves/-/blob/master/2020/CVE-2020-26405.jsonCVE reference · x_refsource_CONFIRM
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.