CVE-2025-27363
An out of bounds write exists in FreeType versions 2.13.0 and below (newer versions of FreeType are not vulnerable) when attempting to parse font subglyph structures related to TrueType GX and variable font files. The vulnerable code assigns a signed short value to an unsigned long and then adds a static value causing it to wrap around and allocate too small of a heap buffer. The code then writes up to 6 signed long integers out of bounds relative to this buffer. This may result in arbitrary code execution. This vulnerability may have been exploited in the wild.
do firstApply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Can a WAF block it? No. This is an out-of-bounds write, a memory-corruption bug. Generic WAF rules do not recognise the input that triggers it; only a rule written for this specific CVE can, and only if the triggering request has a recognisable shape.
Also consider: patch
Based on the weakness type only; no CVE-specific evidence yet. We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.
Is CVE-2025-27363 being exploited?
Yes. CVE-2025-27363 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.
How severe is CVE-2025-27363?
CVE-2025-27363 is rated High with a CVSS score of 8.1. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2025-27363?
Yes. A fix has been recorded for CVE-2025-27363. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2025-27363 affect?
CVE-2025-27363 affects freetype:freetype, debian:debian_linux. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
- affected<= 2.13.0
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.
public exploits
Unvetted proof-of-concept code on GitHub: 3 GitHub proofs of concept
Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.
cisa ssvc
- exploitation
- active
- automatable
- no
- technical impact
- total
Assessed by CISA 7 May 2025 (SSVC 2.0.3).
timeline
- 11 Mar 2025Published
- 23 Mar 2025First proof-of-concept repository on GitHub (unvetted) · 11 days later
- 6 May 2025Added to CISA KEV (exploited in the wild) · 44 days later
- 7 May 2025CISA SSVC assessment: exploitation active · 1 day later
- 27 May 2025CISA remediation due date (US federal agencies) · 20 days later
- 19 Apr 2026CVE record last updated · 328 days (about 11 months) later
- 2 Nov 2026Analysed by vulneraibility.com · 197 days (about 7 months) later
- Advisorysource.android.com /docs/security/bulletin/2025-05-01
- Linkfacebook.com /security/advisories/cve-2025-27363
- Linkcisa.gov /known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-27363
- Linkopenwall.com /lists/oss-security/2025/03/13/1
- Linkopenwall.com /lists/oss-security/2025/03/13/2
- Linkopenwall.com /lists/oss-security/2025/03/13/3
- Linkopenwall.com /lists/oss-security/2025/03/13/8
- Linkopenwall.com /lists/oss-security/2025/03/13/11
Show 9 more
- Linkopenwall.com /lists/oss-security/2025/03/13/12
- Linkopenwall.com /lists/oss-security/2025/03/14/1
- Linkopenwall.com /lists/oss-security/2025/03/14/2
- Linkopenwall.com /lists/oss-security/2025/03/14/3
- Linkopenwall.com /lists/oss-security/2025/03/14/4
- Linklists.debian.org /debian-lts-announce/2025/03/msg00030.html
- Linkopenwall.com /lists/oss-security/2025/05/06/3
- Linkopenwall.com /lists/oss-security/2026/04/16/5
- Linkopenwall.com /lists/oss-security/2026/04/19/3
sources
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- CISA KEV catalog: exploitation, date added, due date
- CISA Vulnrichment (ADP): SSVC decision points
- FIRST EPSS: exploit probability and percentile
- PoC-in-GitHub: GitHub repositories that claim a proof of concept
- Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.