CVE-2026-3805: use after free in SMB connection reuse
Vulnerability summary
CVE-2026-3805 is a high (CVSS 7.5) Use After Free vulnerability in curl. EPSS estimates a 0.84% chance of exploitation in the next 30 days, higher than 57.8% of scored vulnerabilities. 1 public exploit is recorded.
Public exploit (reference, Date unknown)
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 12 · Related 11Timeline
- 11-03-2026PublishedVulnerability first disclosed.
- 15-09-2026Last modifiedVulnerability information updated.
Description
When doing a second SMB request to the same host again, curl would wrongly use a data pointer pointing into already freed memory.
CVSS metrics
5 scores · 5 sources · 1 version- OSV · AlpineEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.84%
Chance of exploitation in the next 30 days
Percentile
58%
Versus all other CVEs
30-day change
Decrease -0.11 pp
From 0.95% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
1 foundExploit Reference (hackerone.com)
Maturity: unknown
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Alpine1 product
- curl≥ 8.13.0, < 8.14.1-r3 | ≥ 8.13.0, < 8.14.1-r4 | ≥ 8.13.0, < 8.19.0-r0
Curl1 product
- curl≥ 8.13.0, < 8.14.2 | ≥ 8.15.0, < 8.16.1 | ≥ 8.17.0, < 8.19.0 | ≥ f4831daa9b2a97e8a2921d6b62cc4dfdd0d8646e, < e090be9f73a7a71459ef678c7cc4b1f75e3ea883 | 8.18.0 | 8.17.0 | 8.16.0 | 8.15.0 | 8.14.1 | 8.14.0 | 8.13.0
Debian1 product
- curl< 8.14.1-2+deb13u4 | < 8.19.0-1
Haxx1 product
- curl≥ 8.13.0, < 8.19.0
Ubuntu1 product
- curl< 8.14.1-2ubuntu1.2
5 vendors · 5 products
References
9 links- curl.se/docs/CVE-2026-3805.jsonVendor Advisory
