Error-response disclosure via omitted cache controls
Published Oct 28, 2025 · Updated Oct 28, 2025
Cache-control omission in Discourse before 3.5.2 allows remote attackers to expose error responses through shared proxy caches. ApplicationController applied dont_cache_page as an after-action, so exceptions bypassed it; public-exception middleware also serialized headers before cache controls were finalized. Latest-channel builds through 3.6.0.beta2-latest are also affected, and exploitation requires an intermediary cache to store an attacker-induced error response.
Summary
What happened
Cache-control omission in Discourse before 3.5.2 allows remote attackers to expose error responses through shared proxy caches. ApplicationController applied dont_cache_page as an after-action, so exceptions bypassed it; public-exception middleware also serialized headers before cache controls were finalized. Latest-channel builds through 3.6.0.beta2-latest are also affected, and exploitation requires an intermediary cache to store an attacker-induced error response.
The record
- CVE
- CVE-2025-61598
- Published
- Oct 28, 2025
- Updated
- Oct 28, 2025
- Vendor
- Discourse
- Product
- Discourse
- Classifications
- CWE-524, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Oct 28, 2025CVE publishedPublication date reported by the CVE source.
- Oct 28, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 3.6.0.beta1, < 3.6.0.beta2
- Affected versionversion=< 3.6.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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