How severe is GHSA-hjr9-wj7v-7hv8?

No CVSS score has been assigned to GHSA-hjr9-wj7v-7hv8 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-hjr9-wj7v-7hv8?

GHSA-hjr9-wj7v-7hv8 affects the following packages: github.com/bishopfox/sliver (Go). Ecosystems affected: Go.

How do I fix GHSA-hjr9-wj7v-7hv8?

The records we use list no patched version of github.com/bishopfox/sliver for GHSA-hjr9-wj7v-7hv8. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range.

How do I detect GHSA-hjr9-wj7v-7hv8 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/bishopfox/sliver, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-hjr9-wj7v-7hv8 if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is GHSA-hjr9-wj7v-7hv8 actively exploited in the wild?

No public exploit code has been indexed for GHSA-hjr9-wj7v-7hv8 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was GHSA-hjr9-wj7v-7hv8 published, and has it been updated?

GHSA-hjr9-wj7v-7hv8 was published on January 5, 2026 and was last updated on February 3, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹 Go

Not in CISA KEV

Sliver Vulnerable to Pre-Auth Memory Exhaustion via NoEncoder BypassGHSA-hjr9-wj7v-7hv8

GHSA-hjr9-wj7v-7hv8 is a security vulnerability in github.com/bishopfox/sliver. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.

Also known asGO-2026-4280

Published

Jan 5, 2026

Updated

Feb 3, 2026

Affected

1 pkg

Patched

None yet

Exploits

None indexed

Exploitation data as of Feb 3, 2026 · OSV.dev, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected

🐹github.com/bishopfox/sliver

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

Summary

A specially crafted nonce routes unauthenticated requests through the NoEncoder path, where startSessionHandler() reads the entire request body without limits, allowing attacker-driven memory exhaustion and process crash.

Details

server/encoders/encoders.go: EncoderFromNonce() returns NoEncoder when nonce % 65537 == 0 (lines 254-264); NoEncoder is a passthrough (util/encoders/nop.go:22-32).
server/c2/http.go: anonymousHandler() routes requests with any encoder (including NoEncoder) to startSessionHandler() (lines 551-562).
server/c2/http.go: startSessionHandler() uses io.ReadAll(req.Body) without a size cap (lines 564-643), unlike the authenticated path that uses io.LimitedReader (readReqBody(), lines 708-732).

PoC

An attacker could send an HTTP POST with a nonce that is a multiple of 65537 (e.g., ?q=65537) so it is handled by startSessionHandler() with a NoEncoder, and advertise a very large Content-Length while streaming data. Because this handler uses io.ReadAll(req.Body) without a size limit, the server is expected to allocate large amounts of memory and may exhaust available RAM, leading to process termination on typical deployments.

Impact

Unauthenticated remote DoS: attacker can crash the Sliver HTTP listener, dropping all active sessions and locking out operators until restart. No credentials or non-default config required.

Affected Packages

1 total

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/bishopfox/sliver`	≥ 1.5.0	No fix

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/bishopfox/sliver, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
The records we use list no patched version of github.com/bishopfox/sliver for GHSA-hjr9-wj7v-7hv8. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range.
Mitigate without a patch
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Frequently Asked Questions

### Summary A specially crafted nonce routes unauthenticated requests through the NoEncoder path, where `startSessionHandler()` reads the entire request body without limits, allowing attacker-driven memory exhaustion and process crash. ### Details - `server/encoders/encoders.go`: `EncoderFromNonce()` returns NoEncoder when `nonce % 65537 == 0` (lines 254-264); NoEncoder is a passthrough (`util/encoders/nop.go:22-32`). - `server/c2/http.go`: `anonymousHandler()` routes requests with any encoder (including NoEncoder) to `startSessionHandler()` (lines 551-562). - `server/c2/http.go`: `startSessi

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