CVE-2025-32797: conda-build · Insecure Inherited Permissions
Affects conda-buildSource CVE Database V5
Not known to be exploited · CVSS 6.0 Medium : upgrade to 25.3.1 when convenient.
Data as of 26 Oct 2026, 10:12 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 25.3.1
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 16 Jun 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
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
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade conda-build to 25.3.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
PyPIconda-buildpkg:pypi/conda-buildOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
- Upgrade conda-build to version 25.3.1 or later immediately to apply the official patch that corrects file permissions and implements atomic file creation.
- Until patching is possible, manually change the permissions of the conda_build.sh script to 0o700 immediately after creation to restrict access to the owner only, preventing unauthorized overwrites.
- Implement filesystem monitoring to detect rapid file modifications or creations in build directories, enabling early detection of potential exploitation attempts.
- Restrict filesystem access on shared systems by enforcing strict user isolation and limiting write permissions to build directories only to trusted users.
- Where feasible, run conda-build processes within isolated containers or virtual machines to contain potential exploitation impact.
- Review and harden CI/CD pipeline configurations to ensure build scripts are not exposed to unauthorized users and that build environments are ephemeral and isolated.
- Educate developers and system administrators about the risks of race conditions and insecure file permissions in build tools to promote proactive security practices.
Description
Conda-build contains commands and tools to build conda packages. Prior to version 25.3.1, the write_build_scripts function in conda-build creates the temporary build script conda_build.sh with overly permissive file permissions (0o766), allowing write access to all users. Attackers with filesystem access can exploit a race condition to overwrite the script before execution, enabling arbitrary code execution under the victim's privileges. This risk is significant in shared environments, potentially leading to full system compromise. Even with non-static directory names, attackers can monitor parent directories for file creation events. The brief window between script creation (with insecure permissions) and execution allows rapid overwrites. Directory names can also be inferred via timestamps or logs, and automation enables exploitation even with semi-randomized paths by acting within milliseconds of detection. This issue has been patched in version 25.3.1. A workaround involves restricting conda_build.sh permissions from 0o766 to 0o700 (owner-only read/write/execute). Additionally, use atomic file creation (write to a temporary randomized filename and rename atomically) to minimize the race condition window.
References
- github.com/conda/conda-build/security/advisories/GHSA-vfp6-3v8g-vcmm (opens in a new tab)
- github.com/conda/conda-build/pull/5 (opens in a new tab)
- github.com/conda/conda-build/commit/d246e49c8f45e8033915156ee3d77769926f3c2e (opens in a new tab)
- github.com/conda/conda-build/blob/3f06913bba22c4e1ef1065df9e00d86ac97f087c/conda_build/build.py (opens in a new tab)