CVE-2026-102944 — cpp-httplib: Cookie header leaked on cross-origin redirect
cpp-httplib is a C++ header-only HTTP/HTTPS library. Prior to 0.51.0, create_redirect_client() removes Host, Proxy-Authorization, and Authorization headers when following a cross-origin 301, 302, 307, or 308 redirect but leaves Cookie headers attached. detail::redirect() copies the request for those redirect codes, so cookies supplied directly or through default_headers_ are sent to the redirect target. An attacker who controls a redirect response, or a network position for a non-HTTPS origin, can receive session cookies intended for the original origin. A 303 redirect is not affected because that path clears all request headers. This issue is fixed in version 0.51.0.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.4% (30-day exploitation probability)+4
- Technical severity (high)+6
- CISA SSVC: exploitation "poc"+5
- Automatable exploitation (SSVC)+3
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.
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.
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 (authentication), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Yhirose | Cpp-httplib | version < 0.51.0 | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
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 |
|---|---|---|---|---|---|
| 7.5 | CVSS 3.1 | High | 3.9 | 3.6 | security-advisories@github.com via NIST National Vulnerability Database |
| 7.5 | CVSS 3.1 | High | — | — | GitHub_M via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N (score shown at the top: security-advisories@github.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
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).
- Review authentication logs: logins without MFA, anomalous sessions and recently created accounts.
Timeline
What happened to this CVE, newest first.
- 2026
- SSVC assessment updated
- Affected products added · yhirose/cpp-httplib
- Record published
- CVSS changed · 7.5
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× References added · Oct 14, 2026 – Oct 14, 2026
- 1× Official description updated · Oct 14, 2026 – Oct 14, 2026
References
3 on the record
Elsewhere on this site
Related CVEs (same products)
- Low CVE-2026-103930 cpp-httplib open_stream serializes CRLF in request target into HTTP request line 1d
- High CVE-2026-77358 cpp-httplib: Use-after-free of TLS session in WebSocketClient::shutdown_and_close() Aug 27, 2026
- Medium CVE-2026-77341 cpp-httplib: CRLF injection via unvalidated HTTP trailer headers in chunked response writing Aug 27, 2026
- 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
- 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-2026-102944 is "cpp-httplib: Cookie header leaked on cross-origin redirect", 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 7.5 describes technical severity. EPSS 0.36% 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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