CVE-2023-27592

CVE-2023-27592 is a medium-severity vulnerability in Miniflux Project Miniflux with a CVSS 3.x base score of 4.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Description

Miniflux is a feed reader. Since v2.0.25, Miniflux will automatically proxy images served over HTTP to prevent mixed content errors. When an outbound request made by the Go HTTP client fails, the `html.ServerError` is returned unescaped without the expected Content Security Policy header added to valid responses. By creating an RSS feed item with the inline description containing an `<img>` tag with a `srcset` attribute pointing to an invalid URL like `http:a<script>alert(1)</script>`, we can coerce the proxy handler into an error condition where the invalid URL is returned unescaped and in full. This results in JavaScript execution on the Miniflux instance as soon as the user is convinced (e.g. by a message in the alt text) to open the broken image. An attacker can execute arbitrary JavaScript in the context of a victim Miniflux user when they open a broken image in a crafted RSS feed. This can be used to perform actions on the Miniflux instance as that user and gain administrative access to the Miniflux instance if it is reachable and the victim is an administrator. A patch is available in version 2.0.43. As a workaround sisable image proxy; default value is `http-only`.

Frequently asked questions

What is CVE-2023-27592?
Miniflux is a feed reader. Since v2.0.25, Miniflux will automatically proxy images served over HTTP to prevent mixed content errors. When an outbound request made by the Go HTTP client fails, the `html.ServerError` is returned unescaped without the expected Content Security Policy header added to valid responses. By creating an RSS feed item with the inline description containing an `<img>` tag with a `srcset` attribute pointing to an invalid URL like `http:a<script>alert(1)</script>`, we can coerce the proxy handler into an error condition where the invalid URL is returned unescaped and in full. This results in JavaScript execution on the Miniflux instance as soon as the user is convinced (e.g. by a message in the alt text) to open the broken image. An attacker can execute arbitrary JavaScript in the context of a victim Miniflux user when they open a broken image in a crafted RSS feed. This can be used to perform actions on the Miniflux instance as that user and gain administrative access to the Miniflux instance if it is reachable and the victim is an administrator. A patch is available in version 2.0.43. As a workaround sisable image proxy; default value is `http-only`.
How severe is CVE-2023-27592?
CVE-2023-27592 has a CVSS 3.x base score of 4.8, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2023-27592 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-27592?
CVE-2023-27592 affects Miniflux Project Miniflux. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-27592?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-27592 published?
CVE-2023-27592 was published on 2023-03-17 and last updated on 2026-06-17.

References

Affected products (1)

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