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, 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)?

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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-hjr9-wj7v-7hv8 can be triaged on real exposure rather than presence alone.

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

GHSA-hjr9-wj7v-7hv8 — sliver

GHSA-hjr9-wj7v-7hv8 is a security vulnerability in github.com/bishopfox/sliver. No vendor fix is recorded yet; mitigation options are listed below.

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

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
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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-hjr9-wj7v-7hv8 can be triaged on real exposure rather than presence alone.

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 Security finds GHSA-hjr9-wj7v-7hv8 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

Scan my dependencies How O3 SCA works