# CVE-2026-27808: Mailpit is Vulnerable to Server-Side Request Forgery (SSRF) via Link Check API > Attackers can exploit the Link Check API to perform Server-Side Request Forgery, accessing internal resources and bypassing network restrictions. - **Severity:** Medium 5.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 25 Feb 2026 - **Updated:** 26 Feb 2026 - **Also known as:** GHSA-mpf7-p9x7-96r3, GO-2026-4558 ## What is CVE-2026-27808? CVE-2026-27808 is a medium-severity server-side request forgery vulnerability in axllent mailpit, published on 25 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description Mailpit is an email testing tool and API for developers. Prior to version 1.29.2, the Link Check API (/api/v1/message/{ID}/link-check) is vulnerable to Server-Side Request Forgery (SSRF). The server performs HTTP HEAD requests to every URL found in an email without validating target hosts or filtering private/internal IP addresses. The response returns status codes and status text per link, making this a non-blind SSRF. In the default configuration (no authentication on SMTP or API), this is fully exploitable remotely with zero user interaction. This is the same class of vulnerability that was fixed in the HTML Check API (CVE-2026-23845 / GHSA-6jxm-fv7w-rw5j) and the screenshot proxy (CVE-2026-21859 / GHSA-8v65-47jx-7mfr), but the Link Check code path was not included in either fix. Version 1.29.2 fixes this vulnerability. Weakness: CWE-918 (Server-Side Request Forgery) ## Which versions are affected by CVE-2026-27808? 3 open source packages ship an affected version, including github.com/axllent/mailpit. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `github.com/axllent/mailpit` | Go | All versions | 1.29.2 | | `github.com/axllent/mailpit` | Go | All versions | 1.29.2 | | `github.com/axllent/mailpit` | Go | All versions | 1.29.2 | Products: Axllent Mailpit. ## How do I fix CVE-2026-27808? Upgrade github.com/axllent/mailpit to 1.29.2 or later. ## Is CVE-2026-27808 being exploited? It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-27808 exists. ## Other vulnerabilities in axllent mailpit - [CVE-2026-45713](https://insights.sbomify.com/CVE-2026-45713/): Mailpit: Unauthenticated remote memory-exhaustion DoS via unlimited SMTP DATA and /api/v1/send body sizes (high 7.5) - [CVE-2026-22689](https://insights.sbomify.com/CVE-2026-22689/): Mailpit is vulnerable to Cross-Site WebSocket Hijacking (CSWSH) allowing unauthenticated access to emails (medium 6.5) - [CVE-2026-45711](https://insights.sbomify.com/CVE-2026-45711/): Mailpit: Path traversal & arbitrary file write in mailpit dump --http via attacker-controlled message IDs (medium 5.9) - [CVE-2026-45712](https://insights.sbomify.com/CVE-2026-45712/): Mailpit: Concurrent map read & write in proxy CSS rewriter - remote unauth crash (fatal error: concurrent map read and map write) (medium 5.9) - [CVE-2026-45709](https://insights.sbomify.com/CVE-2026-45709/): Mailpit has an incomplete fix for GHSA-6jxm: HTML check still permits SSRF to private/loopback/IMDS via missing IP-filter dialer (medium 5.8) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-27808 and fix it if it is affected. What it is: CVE-2026-27808 is a medium-severity server-side request forgery vulnerability in axllent mailpit, published on 25 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-27808 exists. Affected packages and fixed versions: - github.com/axllent/mailpit (Go): affected all versions; fixed in 1.29.2 - github.com/axllent/mailpit (Go): affected all versions; fixed in 1.29.2 - github.com/axllent/mailpit (Go): affected all versions; fixed in 1.29.2 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-27808/ (Markdown: https://insights.sbomify.com/CVE-2026-27808/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-27808 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-27808 - OSV: https://osv.dev/vulnerability/CVE-2026-27808 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-27808/ Summaries are generated and may contain mistakes; the official description above is the record.