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?

No patched version of github.com/bishopfox/sliver has shipped for GHSA-hjr9-wj7v-7hv8 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.

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. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

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

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-hjr9-wj7v-7hv8?

O3 pinpoints whether GHSA-hjr9-wj7v-7hv8 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

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

GHSA-hjr9-wj7v-7hv8

Sliver Vulnerable to Pre-Auth Memory Exhaustion via NoEncoder Bypass

Also known asGO-2026-4280

Published

Jan 5, 2026

Updated

Feb 3, 2026

Affected

1 pkg

Patched

None yet

Exploits

None indexed

Blast Radius

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. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of github.com/bishopfox/sliver has shipped for GHSA-hjr9-wj7v-7hv8 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-hjr9-wj7v-7hv8 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-hjr9-wj7v-7hv8. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

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

O3 Security · Impact-Aware SCA

Is GHSA-hjr9-wj7v-7hv8 in your dependencies?

O3 detects GHSA-hjr9-wj7v-7hv8 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works