CVE-2015-8371
Composer allows cache poisoning from other projects built on the same host
Composer before 2016-02-10 allows cache poisoning from other projects built on the same host. This results in attacker-controlled code entering a server-side build process. The issue occurs because of the way that dist packages are cached. The cache key is derived from the package name, the dist type, and certain other data from the package repository (which may simply be a commit hash, and thus can be found by an attacker). Versions through 1.0.0-alpha11 are affected, and 1.0.0 is unaffected.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
8.8
Composer before 2016-02-10 allows cache poisoning from other projects built on the same host. This results in attacker-controlled code entering a server-side build process. The issue occurs because of the way that dist packages are cached. The cache key is derived from the package name, the dist type, and certain other data from the package repository (which may simply be a commit hash, and thus can be found by an attacker). Versions through 1.0.0-alpha11 are affected, and 1.0.0 is unaffected.
- Record
CVE-2015-8371- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-345
- Updated
- 2026-11-02
CVE List No score
Composer before 2016-02-10 allows cache poisoning from other projects built on the same host. This results in attacker-controlled code entering a server-side build process. The issue occurs because of the way that dist packages are cached. The cache key is derived from the package name, the dist type, and certain other data from the package repository (which may simply be a commit hash, and thus can be found by an attacker). Versions through 1.0.0-alpha11 are affected, and 1.0.0 is unaffected.
- Record
CVE-2015-8371- Updated
- 2026-11-02
EUVDEUVD-2023-2452 No score
Composer before 2016-02-10 allows cache poisoning from other projects built on the same host. This results in attacker-controlled code entering a server-side build process. The issue occurs because of the way that dist packages are cached. The cache key is derived from the package name, the dist type, and certain other data from the package repository (which may simply be a commit hash, and thus can be found by an attacker). Versions through 1.0.0-alpha11 are affected, and 1.0.0 is unaffected.
- Record
EUVD-2023-2452- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-725m-w832-q973
8.8
Composer allows cache poisoning from other projects built on the same host
Composer before 2016-02-10 allows cache poisoning from other projects built on the same host. This results in attacker-controlled code entering a server-side build process. The issue occurs because of the way that dist packages are cached. The cache key is derived from the package name, the dist type, and certain other data from the package repository (which may simply be a commit hash, and thus can be found by an attacker). Versions through 1.0.0-alpha11 are affected, and 1.0.0 is unaffected.
- Record
GHSA-725m-w832-q973- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-345
- Updated
- 2026-11-02
OSV
8.8
Composer before 2016-02-10 allows cache poisoning from other projects built on the same host. This results in attacker-controlled code entering a server-side build process. The issue occurs because of the way that dist packages are cached. The cache key is derived from the package name, the dist type, and certain other data from the package repository (which may simply be a commit hash, and thus can be found by an attacker). Versions through 1.0.0-alpha11 are affected, and 1.0.0 is unaffected.
- Record
CVE-2015-8371- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVDEBIAN-CVE-2015-8371
8.8
Composer before 2016-02-10 allows cache poisoning from other projects built on the same host. This results in attacker-controlled code entering a server-side build process. The issue occurs because of the way that dist packages are cached. The cache key is derived from the package name, the dist type, and certain other data from the package repository (which may simply be a commit hash, and thus can be found by an attacker). Versions through 1.0.0-alpha11 are affected, and 1.0.0 is unaffected.
- Record
DEBIAN-CVE-2015-8371- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVGHSA-725m-w832-q973
8.8
Composer allows cache poisoning from other projects built on the same host
Composer before 2016-02-10 allows cache poisoning from other projects built on the same host. This results in attacker-controlled code entering a server-side build process. The issue occurs because of the way that dist packages are cached. The cache key is derived from the package name, the dist type, and certain other data from the package repository (which may simply be a commit hash, and thus can be found by an attacker). Versions through 1.0.0-alpha11 are affected, and 1.0.0 is unaffected.
- Record
GHSA-725m-w832-q973- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-345
- Updated
- 2026-11-02
OSVUBUNTU-CVE-2015-8371
8.8
Composer before 2016-02-10 allows cache poisoning from other projects built on the same host. This results in attacker-controlled code entering a server-side build process. The issue occurs because of the way that dist packages are cached. The cache key is derived from the package name, the dist type, and certain other data from the package repository (which may simply be a commit hash, and thus can be found by an attacker). Versions through 1.0.0-alpha11 are affected, and 1.0.0 is unaffected.
- Record
UBUNTU-CVE-2015-8371- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
composer/composerPackagist |
through 1.0.0-alpha11 | 1.0.0 |
composerDebian:12 |
before 1.0.0~alpha11-3 | 1.0.0~alpha11-3 |
composerDebian:13 |
before 1.0.0~alpha11-3 | 1.0.0~alpha11-3 |
composerDebian:14 |
before 1.0.0~alpha11-3 | 1.0.0~alpha11-3 |
composer/composerPackagist |
before 1.0.0, plus listed versions 1.0.0-alpha11.0.0-alpha101.0.0-alpha111.0.0-alpha21.0.0-alpha3 Show 8 moreShow less1.0.0-alpha41.0.0-alpha51.0.0-alpha61.0.0-alpha71.0.0-alpha81.0.0-alpha91.0.0-beta11.0.0-beta2 |
1.0.0 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected | ||
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2015-8371 is a high vulnerability (CVSS 8.8) in Getcomposer Composer, published September 21, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.72%, the 54th percentile. Fixed in composer/composer 1.0.0.
References
flyingmana.de/blog_en/2016/02/14/composer_cache_injection_vulnerability_cve_2015_8371.html
github.com/FriendsOfPHP/security-advisories/blob/e26be423c5bcfdb38478d2f92d1f928c15afb561/composer/composer/CVE-2015-8371.yaml
gitlab.com/gitlab-org/advisories-community/-/blob/main/packagist/composer/composer/CVE-2015-8371.yml
github.com/composer/composer
nvd.nist.gov/vuln/detail/CVE-2015-8371
github.com/FriendsOfPHP/security-advisories/blob/master/composer/composer/CVE-2015-8371.yaml