vulnerability / NVI-00002178 / Revision 2
guzzlehttp/psr7 has CRLF Injection via URI Host Component
OSV carries this publisher advisory for guzzlehttp/psr7. This is an aggregated source copy; consult the original publisher and compare update dates.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
0.190%
FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.08689. Missing scores are unknown.
As of · FIRST EPSS
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
guzzlehttp/psr7
source listedECOSYSTEM: introduced 0; fixed 2.10.2
## Impact `guzzlehttp/psr7` did not reject ASCII control characters, whitespace, or DEL in first-party URI host components. The issue requires a PSR-7 request to be serialized into a raw HTTP/1.x message, for example with `GuzzleHttp\Psr7\Message::toString()` or an equivalent custom serializer. Creating a `Uri`, `Request`, or other PSR-7 object alone is not sufficient. The malformed host must be copied into the serialized `Host` header without further validation. A vulnerable flow is: 1. An application accepts a user-controlled URL. 2. The URL is used to construct a PSR-7 `Uri` or `Request`. 3. The host component contains CRLF or another header-unsafe character. 4. The request is serialized into a raw HTTP/1.x message without an explicit `Host` header. 5. The host is copied into the serialized `Host` header. 6. The serialized request is written to the network or otherwise processed by software that does not independently reject the malformed host. In that flow, an attacker can cause the serialized request to contain additional attacker-controlled header lines. For example, a host containing `"\r\nX-Injected: yes"` can cause the generated `Host` header to span multiple HTTP head
03 / Response
What to do next
- vendor patch
The original advisory lists fixed boundaries 2.10.2 for guzzlehttp/psr7. Confirm the publisher’s latest guidance.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database via OSV
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. FIRST EPSS
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-hq7v-mx3g-29hw ↗
GitHub Advisory Database via OSV · vendor advisory
Observed . GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.
- CVE-2026-49214 ↗
FIRST EPSS · official catalog
Observed . FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 2 ·
Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.