CVE-2019-15608
The package integrity validation in yarn < 1.19.0 contains a TOCTOU vulnerability where the hash is computed before writing a package to cache.
Does this matter?
Lower severity and a low EPSS score (1.84%). Track it; it rarely justifies an emergency change on its own.
Description
The package integrity validation in yarn < 1.19.0 contains a TOCTOU vulnerability where the hash is computed before writing a package to cache. It's not computed again when reading from the cache. This may lead to a cache pollution attack.
- CVSS 3.1
- 5.9 MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
- EPSS
- 1.84% probability · 79th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-840, CWE-367
- Affected
- yarnpkg/yarn
- Source
- support@hackerone.com
EPSS 1.8% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/yarnpkg/yarn/blob/master/CHANGELOG.md#1190
- https://github.com/yarnpkg/yarn/commit/0474b8c66a8ea298f5e4dedc67b2de464297ad1c
- https://hackerone.com/reports/703138Exploit, Mitigation, Third Party Advisory
- https://github.com/yarnpkg/yarn/blob/master/CHANGELOG.md#1190
- https://github.com/yarnpkg/yarn/commit/0474b8c66a8ea298f5e4dedc67b2de464297ad1c
- https://hackerone.com/reports/703138Exploit, Mitigation, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.