CVE-2026-43965: Gleam · Path Traversal
Affects GleamSource CVE Database V5
Public exploit available · CVSS 5.6 Medium : upgrade to 1.17.0 as a priority.
Data as of 10 Nov 2026, 19:35 UTC
Thin evidence
One scorer or none| CNA (EEF) | CVSS 4.0 | 5.6 |
|---|
- CISA SSVC
- Exploitation
- Proof of concept is public or traded
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-06-02.
- Patch
- Available – fixed in 1.17.0, v1.17.0-scratch, v1.17.0-node-slim +9
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
t = 0 is the CVE’s publication on cve.org
Disclosed: evidence found.
CVE published 2 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
CISA SSVC: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
Timeline
CVE ID reserved
by Erlang Ecosystem Foundation
, 29 days before disclosure
CVE published
on cve.org
, t = 0
CISA SSVC assessment
proof of concept public
, 1 hour after disclosure
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA SSVC, the Metasploit, Exploit-DB and nuclei-templates index as of 10 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Gleamgleam | Affected
| Fixed in
|
| Gleamgleam-lang/gleam | Affected
| Fixed in
|
| Gleamgleam-lang/gleam | Affected
| Fixed in
|
CPE configurations (1)
cpe:2.3:a:gleam-lang:gleam:*:*:*:*:*:*:*:*
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available in Gleam version 1.17.0 and all its platform variants. Users should upgrade to version 1.17.0 or later to remediate this vulnerability. Until upgraded, avoid running 'gleam deps download' on untrusted projects or repositories that may contain malicious build/packages/packages.toml files.
Description
CVE-2026-43965 is a path traversal vulnerability in Gleam's dependency management system. It allows an attacker to cause arbitrary directory deletion on a victim's system by crafting malicious build/packages/packages.toml content. The vulnerability arises because package keys from this file are used without validation to construct filesystem paths, enabling traversal outside the intended directory. This affects Gleam versions from 0.18.0-rc1 up to but not including 1.17.0.
References
- github.com/gleam-lang/gleam/security/advisories/GHSA-jqvf-f6p2-wrv3 (opens in a new tab)
- cna.erlef.org/cves/CVE-2026-43965.html (opens in a new tab)
- osv.dev/vulnerability/EEF-CVE-2026-43965 (opens in a new tab)
- github.com/gleam-lang/gleam/commit/ed7aec0484f10d60978b63788c8a6497590855ab (opens in a new tab)
- github.com/gleam-lang/gleam/commit/690ca069817bee5f77a28fc3e360627c1da19291 (opens in a new tab)