GHSA-2phg-qgmm-r638 Sliver has Potential Zip Bomb Denial of Service in GzipEncoder
Unauthenticated remote attackers can crash the Sliver C2 server by sending highly compressed gzip data, exhausting memory and CPU resources.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is GHSA-2phg-qgmm-r638?
GHSA-2phg-qgmm-r638 is a denial of service vulnerability in github.com/bishopfox/sliver, published on 25 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Summary
GzipEncoder does not limit output size when processing compressed data. This allows unauthenticated remote attackers to crash sliver server by sending a http request with highly compressed gzip data (aka zip bomb).
Details
In util/encoders/gzip.go, Decode() method decompresses given data by reading the entire gzip buffer at once without limiting output size.
PoC
data = gzip.compress(bytes(1024 * 1024 * 1024)) * 16
requests.post(f"http://172.17.0.2/{nonce}", data=data)
Impact
Unauthenticated remote attackers can exhaust memory and cpu resource of sliver server and crash it when they have GzipEncoderID, which can be easily retrived from implant's http traffic, or by brute-forcing.
A fixed version is available at https://github.com/BishopFox/sliver/releases/tag/v1.7.2.
Which versions are affected by GHSA-2phg-qgmm-r638?
3 open source packages ship an affected version, including github.com/bishopfox/sliver.
| Package | Affected | Fixed in |
|---|---|---|
github.com/bishopfox/sliver Go | All versions | 1.7.2 |
github.com/bishopfox/sliver Go | All versions | 1.7.2 |
github.com/bishopfox/sliver Go | All versions | 1.7.2 |
How do I fix GHSA-2phg-qgmm-r638?
Upgrade github.com/bishopfox/sliver to 1.7.2 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is GHSA-2phg-qgmm-r638 being exploited?
There is no known exploitation of GHSA-2phg-qgmm-r638 in the wild and no public exploit code.
Sources
Also known as GO-2026-4548.