sglang: Improper Handling of Highly Compressed Data (Data Amplification)
CVE-2026-109226 is a high-severity improper handling of highly compressed data (data amplification) vulnerability in sglang from Sgl-project, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected sglang versions: 0.5.21 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.56% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of sglang you run against the affected versions below, and install the vendor's latest release.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Sgl-project | sglang | 0.5.21 and earlier | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA (vulncheck.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.7 | High | CNA (vulncheck.com) |
| CVSS 3.1 | 7.5 | High | CNA (vulncheck.com) |
Official description
SGLang through 0.5.21 contains a decompression amplification vulnerability in load_audio that allows remote attackers to exhaust memory by submitting highly compressed audio decoded without duration or sample limits. Attackers can supply small FLAC-encoded silence files through audio_url or audio_data inputs that expand into massive PCM buffers, exhausting worker memory and CPU for denial of service.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Handling of Highly Compressed Data (Data Amplification)
The product does not handle or incorrectly handles a compressed input with a very high compression ratio that produces a large output.
More Improper Handling of Highly Compressed Data (Data Amplification) vulnerabilities (CWE-409)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other references
- github.com/sgl-project/sglang
- github.com/sgl-project/sglang/blob/v0.5.21/python/sglang/srt/multimodal/audio_from_video.py#L128
- github.com/sgl-project/sglang/blob/v0.5.21/python/sglang/srt/multimodal/processors/base_processor.py#L996
- github.com/sgl-project/sglang/blob/v0.5.21/python/sglang/srt/utils/common.py#L1783
- github.com/sgl-project/sglang/blob/v0.5.21/python/sglang/srt/utils/common.py#L1801-L1803
- github.com/sgl-project/sglang/issues/43708
- vulncheck.com/advisories/sglang-through-0.5.21-audio-decompression-amplification-via-load-audio
Other vulnerabilities in sglang
- 7.5 High severity
- 8.1 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
Recent Improper Handling of Highly Compressed Data (Data Amplification) vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 8.2 High severity
- 8.2 High severity
- 7.5 High severity
- 8.7 High severity
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