CVE-2023-25193 — hb-ot-layout-gsubgpos

hb-ot-layout-gsubgpos.hh in HarfBuzz through 6.0.0 allows attackers to trigger O(n^2) growth via consecutive marks during the process of looking back for base glyphs when attaching marks.

01What is this vulnerability?

hb-ot-layout-gsubgpos.hh in HarfBuzz through 6.0.0 allows attackers to trigger O(n^2) growth via consecutive marks during the process of looking back for base glyphs when attaching marks.

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

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: 2023-02-04T00:00:00.000Z
• Last modified: 2025-03-25T20:23:16.167Z

09References

• github.com — https://github.com/harfbuzz/harfbuzz/commit/85be877925ddbf34f74a1229f3ca1716bb61…
• chromium.googlesource.com — https://chromium.googlesource.com/chromium/src/+/e1f324aa681af54101c1f2d173d92ad…
• github.com — https://github.com/harfbuzz/harfbuzz/blob/2822b589bc837fae6f66233e2cf2eef0f6ce84…
• lists.fedoraproject.org — https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro…
• lists.fedoraproject.org — https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro…
• security.netapp.com — https://security.netapp.com/advisory/ntap-20230725-0006/