NVD / CVE Program· CNA curl

CVE-2026-3805: use after free in SMB connection reuse

Noroxi assessment

Priority: Monitor (action score 30/100)

Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
Probability of exploitation in the next 30 days: 0.89% (FIRST EPSS); higher than 59.8% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
Fixed version: curl curl 8.14.2, 8.16.1, 8.19.0.

Low priority for now. Upgrade to curl curl 8.14.2, 8.16.1, 8.19.0 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

When doing a second SMB request to the same host again, curl would wrongly use a data pointer pointing into already freed memory.

HighCVSS 7.5 · v3.1—Proof of concept Fix available

Published: Mar 11, 2026
Updated: Sep 15, 2026
EPSS: 0.8% · 59th percentile
CWE: CWE-416

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 30 / 40 · 7.5 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.8%

CISA SSVC decision

Exploitation: proof of concept
Automatable: yes
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
Proof of concept exists, no weaponized module
A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
haxx	curl	cpe:2.3:a:haxx:curl

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

haxx curl8.13.0 and later · before 8.19.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (curl). Independent of NVD's CPE analysis and usually ahead of it.

curl curl
- 8.18.0, 8.17.0, 8.16.0, 8.15.0, 8.14.1, 8.14.0, 8.13.0affected
- 8.13.0 and later · before 8.14.2affected · semver
- 8.15.0 and later · before 8.16.1affected · semver
- 8.17.0 and later · before 8.19.0affected · semver
- f4831daa9b2a97e8a2921d6b62cc4dfdd0d8646e and later · before e090be9f73a7a71459ef678c7cc4b1f75e3ea883affected · git

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Alpine:v3.21	curl	from 8.13.0 · before 8.14.1-r3	8.14.1-r3
Alpine:v3.22	curl	from 8.13.0 · before 8.14.1-r4	8.14.1-r4
Alpine:v3.23	curl	from 8.13.0 · before 8.19.0-r0	8.19.0-r0
Debian:13	curl	before 8.14.1-2+deb13u4	8.14.1-2+deb13u4
Debian:14	curl	before 8.19.0-1	8.19.0-1
openSUSE:Leap 15.6	curl	before 8.14.1-150600.4.40.1	8.14.1-150600.4.40.1
openSUSE:Leap 16.0	curl	before 8.14.1-160000.5.1	8.14.1-160000.5.1
openSUSE:Tumbleweed	curl	before 8.19.0-1.1	8.19.0-1.1
Red Hat:hummingbird:1	curl	before 0:8.19.0-3.hum1	0:8.19.0-3.hum1
Red Hat:hummingbird:1	libcurl	before 0:8.19.0-3.hum1	0:8.19.0-3.hum1
Red Hat:hummingbird:1	libcurl-devel	before 0:8.19.0-3.hum1	0:8.19.0-3.hum1
Red Hat:hummingbird:1	libcurl-minimal	before 0:8.19.0-3.hum1	0:8.19.0-3.hum1
SUSE:Linux Enterprise Installer Updates 15 SP4	curl	before 8.14.1-150400.5.80.1	8.14.1-150400.5.80.1
SUSE:Linux Enterprise Micro 5.2	curl	before 8.14.1-150200.4.103.1	8.14.1-150200.4.103.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7	curl	before 8.14.1-150700.7.14.1	8.14.1-150700.7.14.1
SUSE:Linux Enterprise Server 15 SP6-LTSS	curl	before 8.14.1-150600.4.40.1	8.14.1-150600.4.40.1
SUSE:Linux Enterprise Server 16.0	curl-mini	before 8.14.1-160000.5.1	8.14.1-160000.5.1
SUSE:Linux Micro 6.0	curl	before 8.14.1-5.1	8.14.1-5.1
SUSE:Linux Micro 6.1	curl	before 8.14.1-slfo.1.1_6.1	8.14.1-slfo.1.1_6.1
SUSE:Linux Micro 6.2	curl	before 8.14.1-160000.5.1	8.14.1-160000.5.1

Same product

haxx: all records

Other highest-scoring records for the same primary product.

CVE-2021-22901curl 7.75.0 through 7.76.1 suffers from a use-after-free vulnerability resulting in already freed memory being used when a TLS 1.3 session…
51Plan
CVE-2023-38039When curl retrieves an HTTP response, it stores the incoming headers so that they can be accessed later via the libcurl headers API.
47Plan
CVE-2024-2398HTTP/2 push headers memory-leak
45Plan

Published before and after this one in the same product

← EarlierCVE-2026-3783Mar 11, 2026 · token leak with redirect and netrc
21Monitor
← EarlierCVE-2026-3784Mar 11, 2026 · wrong proxy connection reuse with credentials
26Monitor
Later →CVE-2026-4873May 13, 2026 · connection reuse ignores TLS requirement
23Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
curl curl	8.14.2	Vendor (CNA)
curl curl	8.16.1	Vendor (CNA)
curl curl	8.19.0	Vendor (CNA)
curl curl	e090be9f73a7a71459ef678c7cc4b1f75e3ea883	Vendor (CNA)
alpine:curl	8.14.1-r3 · Alpine:v3.21	Package registry (OSV)
alpine:curl	8.19.0-r0 · Alpine:v3.23	Package registry (OSV)
debian:curl	8.14.1-2+deb13u4 · Debian:13	Package registry (OSV)
opensuse:curl	8.14.1-150600.4.40.1 · openSUSE:Leap 15.6	Package registry (OSV)
red hat:curl	0:8.19.0-3.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:libcurl	0:8.19.0-3.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:libcurl-devel	0:8.19.0-3.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:libcurl-minimal	0:8.19.0-3.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
suse:curl	8.14.1-150200.4.103.1 · SUSE:Linux Enterprise Micro 5.2	Package registry (OSV)
suse:curl	8.14.1-150600.4.40.1 · SUSE:Linux Enterprise Server 15 SP6-LTSS	Package registry (OSV)
suse:curl-mini	8.14.1-160000.5.1 · SUSE:Linux Enterprise Server 16.0	Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
Source	Kind	Date
Proof-of-concept repository on GitHub	stars:0	2026-04-12

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

PublishedMar 11, 2026
First PoCApr 12, 2026+32 d
TodayNov 11, 2026+246 d

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Stefan Eissingremediation developer
Daniel WadePatchstack Bug Bounty Programfinder

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

CVE-2026-10536114 days apartHTTP/2 stream-dependency tree UAF
39Monitor
CVE-2026-18924179 days apartHTTP/2 server push UAF
36Monitor
CVE-2026-80229179 days apartOpenSSL provider use-after-free
30Monitor
CVE-2026-9080114 days apartUAF after pause in socket callback
29Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: none
Integrity: none
Availability: high · the service can be disrupted

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: None
Integrity impact: None
Availability impact: High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

nvd-secondary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

Fix✗ → ✓Sep 28, 2026, 10:11 PM UTC

For records you follow, these changes also arrive as notifications. →

References

curl.se/docs/CVE-2026-3805.html

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records