CVE-2026-78334
What it is
Missing authentication in the streaming RPC path of Apache bRPC (version < 1.18.0) on all platforms allows a remote attacker to bypass server authentication and inject or deliver streaming frames, when a server is configured with an Authenticator. Root Cause: When authentication is configured, streaming RPC frames are consumed directly by the streaming parser (ParseStreamingMessage) and never pass through InputMessenger's authentication hook, so an unauthenticated peer can exchange frames without being authenticated. In addition, a server-accepted stream is bound lazily to the first frame that happens to carry its id, so a stream could accept a frame carrying its id from a socket other than the socket that created the stream. Affected Scenarios: A bRPC server configured with authentication that serves streaming RPC from an untrusted network, or a deployment where a foreign connection can impersonate a stream by id, can be made to accept unauthorized streaming frames. How to Fix: Upgrade bRPC to 1.18.0, which fixes this issue, or apply the patch in PR https://github.com/apache/brpc/pull/3481. Note: The fix rejects streaming frames on server sockets when configured authentication has not completed, and keeps server-accepted streams bound to the socket of their creating RPC and rejects frames arriving from another socket. Authenticated streaming RPC behavior and the wire format are unchanged; only unauthenticated or foreign-socket frames are now rejected.
At a glance
- Exploitability
- Can be exploited over the network without logging in. High risk of data tampering, service disruption.
- Exploit odds
- 0.7% chance of exploitation in the next 30 days (EPSS).
- Fix
- No patch or advisory is linked yet. Look at mitigations or restrict exposure.
Timeline
- ReservedThe CVE id was reserved by its CNA
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.7% in the next 30 days (EPSS).
- Severity: 9.1 CRITICAL (CVSS).
- Fix: none linked yet, which raises it.
Details
- Published
- Last modified
- Exploit probability
- 0.7% · EPSS, next 30 days
- Weakness
- CWE-306 · Missing authentication
- Record status
- Deferred
Attack profile CVSS 3.1 · 9.1
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
Is it in your code?
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