GHSA-hq7v-mx3g-29hw · Severity: medium · Ecosystem: composer — guzzlehttp/psr7 has CRLF Injection via URI Host Component
guzzlehttp/psr7 is a PSR-7 HTTP message library implementation in PHP. Versions prior to 2.10.2 did not reject ASCII control characters, whitespace, or DEL in first-party URI host components. A vulnerable flow is: First, an application accepts a user-controlled URL. Second, the URL is used to construct a PSR-7 `Uri` or `Request`. Third, the host component contains CRLF or another header-unsafe character. Fourth, the host is copied into the PSR-7 `Host` header when no explicit `Host` header is provided. Finally, the request is serialized or sent by an HTTP client 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 header lines. Applications are affected when they use user-controlled URLs for outbound HTTP requests, URL forwarding, proxying, crawling, webhook delivery, or similar request-dispatch flows. In deployments involving HTTP/1.1 connection reuse, proxies, gateways, or load balancers, this malformed request may also contribute to request smuggling or cache poisoning, depending on how downstream components parse the request. The issue is patched in `2.10.2` and later. `1.x` is end-of-life and will not receive a patch. As a workaround, validate and reject all untrusted URI strings before constructing PSR-7 `Uri` or `Request` instances. Reject input containing ASCII control characters, whitespace, or DEL, including CRLF, tab, space, NUL, or DEL characters. Applications that forward requests should also ensure the final HTTP client or serializer rejects invalid URI and header data before writing requests to the network.
Conclusion & alert: CVE-2026-49214 is rated Low Risk (29.3/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.31%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.04% | 0.31% | +0.27% |
| 2 | 2026-06-12 | — | 0.04% | — |
Full EPSS history (2 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.3 | 3.1 | MEDIUM |
|
3.9 | 1.4 | [email protected] |
GHSA-hq7v-mx3g-29hw · Severity: medium · Ecosystem: composer — guzzlehttp/psr7 has CRLF Injection via URI Host Component
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
not yet assigned | CVE-2026-49214 not yet assigned priority: Debian including 1 source packages (php-guzzlehttp-psr7), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 3, resolved 2. | https://security-tracker.debian.org/tracker/CVE-2026-49214 |
ubuntu
|
medium | CVE-2026-49214 medium priority: Ubuntu including 1 source packages (php-guzzlehttp-psr7), 6 status rows across 6 suites (focal, jammy, noble, questing, resolute, upstream): needs-triage 6. | https://ubuntu.com/security/CVE-2026-49214 |
| URL | Tags |
|---|---|
| https://github.com/guzzle/psr7/security/advisories/GHSA-hq7v-mx3g-29hw | Mitigation Vendor Advisory |