CVE-2019-5436 — A heap buffer overflow in the TFTP receiving code allows for DoS or arbitrary code execution in...
A heap buffer overflow in the TFTP receiving code allows for DoS or arbitrary code execution in libcurl versions 7.19.4 through 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 49.7% (30-day exploitation probability)+15
- 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.
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.
- Documented patch — www.openwall.com (NIST National Vulnerability Database)
- Documented patch — curl.haxx.se (NIST National Vulnerability Database)
- Documented patch — www.oracle.com (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, Debian Debian Linux, F5 Traffix Signaling Delivery Controller…).
- Apply the fixed version or the patch documented under Remediation.
- EPSS ahead of 99% 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.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Curl | Curl | version Fixed in 7.65.0 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Debian | Debian Linux | version 9.0version 10.0 | Vulnerable | NIST National Vulnerability Database |
| F5 | Traffix Signaling Delivery Controller | ≥ 5.0.0 and ≤ 5.1.0 | Vulnerable | NIST National Vulnerability Database |
| Fedoraproject | Fedora | version 29 | Vulnerable | NIST National Vulnerability Database |
| Haxx | Libcurl | ≥ 7.19.4 and ≤ 7.64.1 | Vulnerable | NIST National Vulnerability Database |
| Netapp | Hci Management Node | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Netapp | Solidfire | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Netapp | Steelstore Cloud Integrated Storage | versions not specified by the source | Vulnerable | NIST National Vulnerability Database |
| Opensuse | Leap | version 15.1version 42.3version 15.0 | Vulnerable | NIST National Vulnerability Database |
| Oracle | Enterprise Manager Ops Center | version 12.3.3version 12.4.0 | Vulnerable | NIST National Vulnerability Database |
| Oracle | Mysql Server | ≤ 5.7.27≥ 5.7.28 and ≤ 8.0.17 | Vulnerable | NIST National Vulnerability Database |
| Oracle | Oss Support Tools | version 20.0 | Vulnerable | NIST National Vulnerability Database |
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 |
|---|---|---|---|---|---|
| 7.8 | CVSS 3.1 | High | 1.8 | 5.9 | nvd@nist.gov via NIST National Vulnerability Database |
| 7.8 | CVSS 3.1 | High | 1.8 | 5.9 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 via NIST National Vulnerability Database |
| 7.8 | CVSS 3.1 | High | — | — | GitHub, Inc. via GitHub Security Advisories |
| 7.8 | CVSS 3.1 | High | — | — | CISA-ADP via CVE Program (cve.org) e CISA ADP |
| 4.6 | CVSS 2.0 | Medium | 3.9 | 6.4 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (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 49.74%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
- 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
- SSVC assessment updated
- Record published
- Fix documented
- Affected products added · haxx/libcurl, opensuse/leap, fedoraproject/fedora, debian/debian linux, f5/traffix signaling delivery controller, netapp
- CVSS changed · 7.8
- 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
21 on the record
- www.oracle.com/technetwork/security-advisory/cpuoct2019-5072832.html
- curl.haxx.se/docs/CVE-2019-5436.html
- www.openwall.com/lists/oss-security/2019/09/11/6
- seclists.org/bugtraq/2020/Feb/36
- security.gentoo.org/glsa/202003-29
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SMG3
- github.com/advisories/GHSA-8xvc-p9x4-w7jm
- security.netapp.com/advisory/ntap-20190606-0004
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SMG3
- www.oracle.com/security-alerts/cpuapr2020.html
- support.f5.com/csp/article/K55133295
- lists.opensuse.org/opensuse-security-announce/2019-06/msg00008.html
- support.f5.com/csp/article/K55133295
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/SMG3V4
- security.netapp.com/advisory/ntap-20190606-0004/
- www.oracle.com/security-alerts/cpuoct2020.html
- lists.opensuse.org/opensuse-security-announce/2019-06/msg00017.html
- cert-portal.siemens.com/productcert/html/ssa-398330.html
- www.debian.org/security/2020/dsa-4633
- nvd.nist.gov/vuln/detail/CVE-2019-5436
- support.f5.com/csp/article/K55133295
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-92392 HTTP/2 upload Use-After-Free 1d
- High CVE-2026-12996 A use-after-free in OpenVPN 2.6.0 through 2.6.20 and 2.7_alpha1 through 2.7.4 allows remote... Jul 30, 2026
- Medium CVE-2026-14355 ext/openssl: Memory corruption in openssl_encrypt with AES-WRAP-PAD Jul 3, 2026
- High CVE-2026-9080 UAF after pause in socket callback Jul 3, 2026
- High CVE-2026-8932 incomplete mTLS config matching in conn reuse Jul 3, 2026
- Critical CVE-2026-9079 stale proxy password leak Jul 3, 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 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-2019-5436 is "A heap buffer overflow in the TFTP receiving code allows for DoS or arbitrary code execution in...", rated High. It affects Curl (Curl); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.8 describes technical severity. EPSS 49.74% 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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