sglang: Use of Multiple Resources with Duplicate Identifier
CVE-2026-102634 is a high-severity use of multiple resources with duplicate identifier 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: 0.5.20 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 0.58% 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 | 0.5.20 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 0.5.20 in prefill/decode disaggregation mode fails to validate duplicate bootstrap_room fields in /generate requests with Mooncake KV transfer backend. Unauthenticated attackers can send concurrent requests with identical bootstrap_room values to crash scheduler processes or hang other users' requests until transfer timeout.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use of Multiple Resources with Duplicate Identifier
The product uses multiple resources that can have the same identifier, in a context in which unique identifiers are required.
How developers prevent this class of flaw
- Where possible, use unique identifiers. If non-unique identifiers are detected, then do not operate any resource with a non-unique identifier and report the error appropriately.
More Use of Multiple Resources with Duplicate Identifier vulnerabilities (CWE-694)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: partial).
References
Other references
- github.com/sgl-project/sglang
- github.com/sgl-project/sglang/blob/v0.5.20/python/sglang/srt/disaggregation/common/conn.py#L392-L393
- github.com/sgl-project/sglang/blob/v0.5.20/python/sglang/srt/disaggregation/decode.py#L942
- github.com/sgl-project/sglang/blob/v0.5.20/python/sglang/srt/disaggregation/mooncake/conn.py#L2760-L2764
- github.com/sgl-project/sglang/blob/v0.5.20/python/sglang/srt/managers/io_struct.py#L281
- github.com/sgl-project/sglang/issues/40125
- vulncheck.com/advisories/sglang-through-0.5.20-denial-of-service-via-duplicate-bootstrap-room
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 Use of Multiple Resources with Duplicate Identifier vulnerabilities
- 8.1 High severity
- 8.8 High severity
- 8.2 High severity
- 8.1 High severity
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