High Cryptography exploit reference

CVE-2026-32627 — cpp-httplib has a Silent TLS Certificate Verification Bypass on HTTPS Redirect via Proxy

cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.37.2, when a cpp-httplib client is configured with a proxy and set_follow_location(true), any HTTPS redirect it follows will have TLS certificate and hostname verification silently disabled on the new connection. The client will accept any certificate presented by the redirect target — expired, self-signed, or forged — without raising an error or notifying the application. A network attacker in a position to return a redirect response can fully intercept the follow-up HTTPS connection, including any credentials or session tokens in flight. This vulnerability is fixed in 0.37.2.

Published Mar 16, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: GitHub_M

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.3% (30-day exploitation probability)+2
Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.26%

ahead of 16% of scored CVEs · Oct 14, 2026

Affects

Yhirose

Cpp-httplib

CVSS base

8.1

High · 3 source(s)

Prioritization reference: 8.7 provisional

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Yhirose Cpp-httplib).
The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes matching the vulnerability class (cryptography), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Yhirose	Cpp-httplib	< 0.37.2	Vulnerable	NIST National Vulnerability Database
Yhirose	Cpp-httplib	version < 0.37.2	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

High

Privileges required

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
8.7	CVSS 3.1	High	2.2	5.8	security-advisories@github.com via NIST National Vulnerability Database
8.7	CVSS 3.1	High	—	—	GitHub_M via CVE Program (cve.org) e CISA ADP
8.1	CVSS 3.1	High	2.2	5.9	nvd@nist.gov via NIST National Vulnerability Database

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov)

Scoring entities (NIST, CNA, ADP) score independently; each score is shown with its origin. For prioritization we use 8.7 (security-advisories@github.com via NIST National Vulnerability Database) as a conservative provisional reference — not a definitive official score.

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-295 · Improper Certificate Validation

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.26%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Check TLS negotiations and unexpected certificates in the component’s traffic.

web/proxy/WAF logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first.

2026
Affected products added · yhirose/cpp-httplib
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
CVSS changed · 8.1
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
CVE published
Mar 16, 2026 · GitHub_M

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

1 on the record

github.com/yhirose/cpp-httplib/security/advisories/GHSA-c3h8-fqq4-xm4g
Exploit, Vendor Advisory, x_refsource_CONFIRM, NIST National Vulnerability Database

Elsewhere on this site

Yhirose
every CVE for this vendor

Cryptography
same class

CWE-295
other pages naming this weakness

Related CVEs (same products)

Low CVE-2026-103930 cpp-httplib open_stream serializes CRLF in request target into HTTP request line 1d
High CVE-2026-102944 cpp-httplib: Cookie header leaked on cross-origin redirect 1d
High CVE-2026-54919 cpp-httplib: TLS certificate chain verification bypassed for IP-literal hosts on Mbed TLS and wolfSSL backends Jul 10, 2026
High CVE-2026-46527 cpp-httplib: Malicious `X-Forwarded-For` Under Trusted-Proxy Configuration Triggers Empty `vector::front()`, Leading to Undefined Behavior and Server Crash May 29, 2026
Critical CVE-2026-45372 cpp-httplib: HTTP header value percent-decoding in server-side `parse_header` enables CRLF injection May 29, 2026
High CVE-2026-45352 cpp-httplib DoS: Negative chunk-size in chunked Transfer-Encoding May 29, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No fixed version, patch or mitigation documented.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-32627 is "cpp-httplib has a Silent TLS Certificate Verification Bypass on HTTPS Redirect via Proxy", rated High. It affects Cpp-httplib (Yhirose); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.1 describes technical severity. EPSS 0.26% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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