# CVE-2026-77622: Sliver unauthenticated memory exhaustion in HTTP(S) listener

Source: https://junglewise.ai/threats/cve-2026-77622-sliver-unauthenticated-memory-exhaustion-denial-of-service-in  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-05. Updated: 2026-10-15  
License: CC BY 4.0 with a link back

CVE-2026-77622 · Severity: high · CVSS 4 · Published 2026-11-05

Sliver is a command-and-control platform used for red team operations. An attacker can crash a Sliver server by sending a specially crafted large PNG image to an unauthenticated HTTP listener, exhausting all available memory on the host machine. Combined with a small nonce space, this allows attackers to enumerate and exploit any running Sliver HTTP listener without authentication.

Technologies: [Bishopfox Sliver](https://junglewise.ai/threats/technologies/sliver), [github.com/bishopfox/sliver (Go)](https://junglewise.ai/threats/technologies/github-com-bishopfox-sliver). Vendors: [Bishopfox](https://junglewise.ai/threats/vendors/bishopfox), [Go](https://junglewise.ai/threats/vendors/go).

## Quick answers

**Is CVE-2026-77622 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-77622 being exploited in the wild.

**How severe is CVE-2026-77622?** High severity, with a CVSS score of 4, published 5 November 2026.

**Which products and versions are affected?** Bishopfox Sliver prior to patch; github.com/bishopfox/sliver (Go) < 1.7.6, SEMVER:introduced=0,fixed=1.7.6.

**Is there a fix for CVE-2026-77622?** Yes. github.com/bishopfox/sliver (Go): upgrade to 1.7.6 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-77622 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-77622?** Check whether you run Bishopfox Sliver or github.com/bishopfox/sliver (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/bishopfox/sliver (Go): upgrade to 1.7.6 or later

  ```sh
  go get github.com/bishopfox/sliver@v1.7.6
  ```


## Technical details

The vulnerability combines two issues: the PNG decoder accepts unlimited image dimensions without validation, causing unbounded memory allocation during decompression, and the nonce space is only 65,537 values, making brute-force trivial. An unauthenticated attacker on the network can POST a crafted PNG to the HTTP listener endpoint, triggering decompression of a multi-gigabyte image that exhausts system RAM, resulting in denial of service to the entire Sliver server.

## Affected products

- BishopFox Sliver prior to patch

## Identifiers

- CVE-2026-77622
- GHSA-663m-7x7m-g4fw
- GO-2026-6777

## Timeline

- 2026-10-15: disclosed

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- [GO-2026-4899 - Sliver: Nil Pointer Dereference in tunnelCloseHandler causes panic when a reverse tunnel (rportfwd)…](https://junglewise.ai/threats/go-2026-4899-sliver-nil-pointer-dereference-in-tunnelclosehandler-bd83eea8)
- [BishopFox Sliver unauthenticated remote access in MCP interface](https://junglewise.ai/threats/cve-2026-34227-bishopfox-sliver-unauthenticated-remote-access-in-mcp-interface)
- [Sliver: Nil Pointer Dereference in tunnelCloseHandler causes panic when a reverse tunnel (rportfwd) close is attempted](https://junglewise.ai/threats/sliver-nil-pointer-dereference-in-tunnelclosehandler-causes-panic-when-df5d6c15)
- [Sliver Vulnerable to Authenticated OOM via Memory Exhaustion in mTLS/WireGuard Transports](https://junglewise.ai/threats/cve-2026-32941-sliver-vulnerable-to-authenticated-oom-via-memory-exhaustion-in)