Security readout for executives and security teams
Plain-English summary
Mailpit versions before 1.29.2 can be tricked into making web requests to attacker-chosen links found in email messages. In default setups without authentication, a remote attacker may use the Link Check API to probe internal or private network resources. The vendor fixed this in version 1.29.2.
Executive priority
Treat this as a prompt remediation item for exposed development or testing infrastructure. Business impact is mainly internal network reconnaissance or data exposure through SSRF, not direct system takeover based on current sources.
Technical view
CVE-2026-27808 is a CWE-918 SSRF in Mailpit’s /api/v1/message/{ID}/link-check endpoint. The server sends HTTP HEAD requests to URLs found in email content without validating hosts or filtering private/internal IPs. Because responses include status code and text per link, the SSRF is non-blind. Affected versions are Mailpit before 1.29.2.
Likely exposure
Exposure is most relevant where Mailpit is reachable over a network, especially default deployments with unauthenticated SMTP or API access. Internet-exposed developer, CI, or test environments running versions before 1.29.2 should be prioritized.
Exploitation context
The advisory states remote exploitation is possible with no user interaction in default unauthenticated configurations. The CVE is not listed as KEV, and the provided sources do not state active exploitation in the wild.
Researcher notes
This is the Link Check code path for the same vulnerability class previously addressed in Mailpit HTML Check and screenshot proxy issues. The fix is identified in commit 10ad4df8cc0cd9e51dea1b4410009545eef7fbf5 and release v1.29.2.
Mitigation direction
- Upgrade Mailpit to version 1.29.2 or later.
- Restrict network access to Mailpit SMTP and API interfaces.
- Enable authentication where supported and appropriate for the deployment.
- Limit Mailpit egress to internal or sensitive network ranges where feasible.
- Review the vendor advisory and release notes for deployment-specific guidance.
Validation and detection
- Inventory Mailpit deployments and identify versions before 1.29.2.
- Confirm whether Mailpit API or SMTP endpoints are externally reachable.
- Verify upgraded instances report version 1.29.2 or later.
- Review logs for unexpected Link Check API usage.
- Check outbound network logs for unusual Mailpit HEAD requests.
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.
CWE-918: Information exposure and cloud metadata lookup
Information exposure and SSRF weaknesses can make discovery, cloud metadata, and credential material review relevant. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCloud metadata behavior lookup
The CVE wording references SSRF or metadata access, so cloud discovery and credential material review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-27808 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
- Medium
- CVSS
- 5.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N
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:N/UI:N/S:C/C:L/I:N/A:N3.91.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.8MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/axllent/mailpit/security/advisories/GHSA-mpf7-p9x7-96r3CVE reference · x_refsource_CONFIRM
- https://github.com/axllent/mailpit/commit/10ad4df8cc0cd9e51dea1b4410009545eef7fbf5CVE reference · x_refsource_MISC
- https://github.com/axllent/mailpit/releases/tag/v1.29.2CVE reference · x_refsource_MISC
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.
Server-Side Request Forgery (SSRF)
Server-Side Request Forgery (SSRF) represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.