A cache poisoning vulnerability has been found in the Pingora HTTP proxy framework’s default cache key construction. The issue occurs because the default HTTP cache key implementation generates cache keys using only the URI path, excluding critical factors such as the host header (authority). Operators relying on the default are vulnerable to cache poisoning, and cross-origin responses may be improperly served to users.
Impact
This vulnerability affects users of Pingora's alpha proxy caching feature who relied on the default CacheKey implementation. An attacker could exploit this for:
Cloudflare's CDN infrastructure was not affected by this vulnerability, as Cloudflare's default cache key implementation uses multiple factors to prevent cache key poisoning and never made use of the previously provided default.
Mitigation:
We strongly recommend Pingora users to upgrade to Pingora v0.8.0 or higher, which removes the insecure default cache key implementation. Users must now explicitly implement their own callback that includes appropriate factors such as Host header, origin server HTTP scheme, and other attributes their cache should vary on.
Pingora users on previous versions may also remove any of their default CacheKey usage and implement their own that should at minimum include the host header / authority and upstream peer’s HTTP scheme.
This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. A user must be tricked into taking some action. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability none.
The score comes from this vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
CVE-2026-2836 is classified as CWE-345: Insufficient Verification of Data Authenticity. Data is trusted without confirming it really came from the claimed source and was not altered.
CVE-2026-2836 is recorded against 2 packages.
Published on 5 March 2026 and last revised on 17 June 2026. No public exploit is currently recorded for this entry. Record sourced from NVD.
pingora has other advisories on record. If you are patching this one, these are worth checking on the same host:
These advisories are the same class of weakness (CWE-345: Insufficient Verification of Data Authenticity) in other software:
Details
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
Affected Packages
| Software | From version | Fixed in |
|---|---|---|
| pingora | — | 0.8.0 |
| pingora-cache | — | — |
References
Similar Threats
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CVE-2026-2836 is rated CVSS 8.1 High. BotEraser scans your installation against known CVE records and tells you whether this vulnerability applies to the versions you actually run.
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ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.
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