CVE-2019-5435 — An integer overflow in curl's URL API results in a buffer overflow in libcurl 7.62.0 to and...
An integer overflow in curl's URL API results in a buffer overflow in libcurl 7.62.0 to and including 7.64.1.
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 5.7% (30-day exploitation probability)+14
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.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — curl.haxx.se (NIST National Vulnerability Database)
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 (Curl Curl, Haxx Curl).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- Apply the fixed version or the patch documented under Remediation.
- EPSS ahead of 93% of scored CVEs: prioritize it in the patch queue.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
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 |
|---|---|---|---|---|---|
| 3.7 | CVSS 3.0 | Low | 2.2 | 1.4 | nvd@nist.gov via NIST National Vulnerability Database |
| 3.7 | CVSS 3.0 | Low | — | — | GitHub, Inc. via GitHub Security Advisories |
| 4.3 | CVSS 2.0 | Medium | 8.6 | 2.9 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 5.66%
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).
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · curl/curl
- Record published
- Fix documented
- Affected products added · haxx/curl
- CVSS changed · 3.7
- Source status changed · → Modified
- Record created in this database
- 2019
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 14, 2026 – Oct 14, 2026
- 1× Official description updated · Oct 14, 2026 – Oct 14, 2026
References
14 on the record
- curl.haxx.se/docs/CVE-2019-5435.html
- support.f5.com/csp/article/K08125515
- cert-portal.siemens.com/productcert/html/ssa-398330.html
- www.oracle.com/security-alerts/cpuoct2020.html
- security.netapp.com/advisory/ntap-20190606-0004/
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/SMG3V4
- www.oracle.com/security-alerts/cpuapr2020.html
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SMG3
- security.netapp.com/advisory/ntap-20190606-0004
- www.oracle.com/technetwork/security-advisory/cpuoct2019-5072832.html
- nvd.nist.gov/vuln/detail/CVE-2019-5435
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SMG3
- security.gentoo.org/glsa/202003-29
- github.com/advisories/GHSA-fp2w-w5rc-8fxj
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-92392 HTTP/2 upload Use-After-Free 1d
- Medium CVE-2026-7009 OCSP stapling bypass with Apple SecTrust May 13, 2026
- Medium CVE-2026-7168 cross-proxy Digest auth state leak May 13, 2026
- Medium CVE-2026-6429 netrc credential leak with reused proxy connection May 13, 2026
- High CVE-2026-5773 wrong reuse of SMB connection May 13, 2026
- Medium CVE-2026-5545 wrong reuse of HTTP Negotiate connection May 13, 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 CISA SSVC assessment.
- 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-2019-5435 is "An integer overflow in curl's URL API results in a buffer overflow in libcurl 7.62.0 to and...", rated Low. It affects Curl (Curl); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 3.7 describes technical severity. EPSS 5.66% 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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