CVE-2026-67201
CVE-2026-67201 is a high-severity vulnerability with a CVSS 3.x base score of 8.6. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-436.
Key facts
- Severity: High (CVSS 3.x base score 8.6)
- CVSS v4: 7.7
- EPSS exploit prediction: 0% (33rd percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-436
- Published:
- Last modified:
Description
V through 0.5.2, fixed in commit 85859f0, contains a server-side request forgery (SSRF) bypass vulnerability that allows attackers to circumvent host-based allowlists by exploiting a parser differential between net.urllib and net.http. Attackers can craft a URL containing a backslash in the authority section such that net.urllib.parse() extracts the trusted host for allowlist validation while net.http.get() normalizes the backslash and connects to the internal host, enabling access to internal network services that the allowlist was intended to block.
Frequently asked questions
- What is CVE-2026-67201?
- V through 0.5.2, fixed in commit 85859f0, contains a server-side request forgery (SSRF) bypass vulnerability that allows attackers to circumvent host-based allowlists by exploiting a parser differential between net.urllib and net.http. Attackers can craft a URL containing a backslash in the authority section such that net.urllib.parse() extracts the trusted host for allowlist validation while net.http.get() normalizes the backslash and connects to the internal host, enabling access to internal network services that the allowlist was intended to block.
- How severe is CVE-2026-67201?
- CVE-2026-67201 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
- Is CVE-2026-67201 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-67201?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2026-67201 published?
- CVE-2026-67201 was published on 2026-07-29 and last updated on 2026-07-30.
References
- https://github.com/vlang/v/commit/85859f0f3498d4091b38009c45ed390a97eeedc2
- https://github.com/vlang/v/issues/27945
- https://github.com/vlang/v/pull/27947
- https://www.vulncheck.com/advisories/v-ssrf-bypass-via-parser-differential-in-net-urllib-and-net-http
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