CVE-2023-28081 — A bytecode optimization bug in Hermes prior to commit e6ed9c1a4b02dc219de1648f44

A bytecode optimization bug in Hermes prior to commit e6ed9c1a4b02dc219de1648f44cd808a56171b81 could be used to cause an use-after-free and obtain arbitrary code execution via a carefully crafted payload. Note that this is only exploitable in cases where Hermes is used to execute

01What is this vulnerability?

A bytecode optimization bug in Hermes prior to commit e6ed9c1a4b02dc219de1648f44cd808a56171b81 could be used to cause an use-after-free and obtain arbitrary code execution via a carefully crafted payload. Note that this is only exploitable in cases where Hermes is used to execute untrusted JavaScript. Hence, most React Native applications are not affected.

02Affected products

Vendor	Product	Versions
Facebook	Hermes	0

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2023-05-18T21:26:49.822Z
• Last modified: 2025-01-21T20:16:02.965Z

09References

• www.facebook.com — https://www.facebook.com/security/advisories/cve-2023-28081
• github.com — https://github.com/facebook/hermes/commit/e6ed9c1a4b02dc219de1648f44cd808a56171b…