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Security Digest · Vulnerability record · Known exploited

CVE-2025-27363: FreeType Out-of-Bounds Write Vulnerability

Exploited in the wild (CISA KEV). 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.

CISA KEV · added 2025-05-06 CVSS 8.1 High EPSS 27.8% · p98

Updated By erroneo.us Security Desk19 references Seen in the digest for May 6, 2025

Should you act?

Exploited: patch now if you run it

CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

  • Yes, if you run FreeType FreeType. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2025-05-06, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2025-05-27; treat that as the outer limit, not the target.
  • EPSS 27.8%, percentile 98: FIRST’s model estimates a 27.8% chance of exploitation activity in the next 30 days, higher than 98% of all scored CVEs (very high). EPSS is a probability, not a verdict.
  • Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.

What it is

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.

CISA’s summary

FreeType contains an out-of-bounds write vulnerability when attempting to parse font subglyph structures related to TrueType GX and variable font files that may allow for arbitrary code execution.

Weakness type: CWE-787.

Product: FreeType FreeType · Assigned by: facebook · Published: 2025-03-11

Affected and fixed versions

VendorProductAffected versions (per CVE record)
FreeTypeFreeType0.0.0 <= 2.13.0

Severity scores

Scored byCVSSScoreVector
facebook3.18.1 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C/CR:H/IR:H/AR:H/MAV:N/MAC:L/MPR:N/MUI:N/MS:U/MC:H/MI:H/MA:H
  • Attack vector: network (remotely reachable)
  • Attack complexity: high (needs special conditions)
  • Privileges required: none (no login)
  • User interaction: none
  • Scope: unchanged

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

  • CISA KEV: added 2025-05-06; federal due date 2025-05-27. Known ransomware use: Unknown.
  • CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
  • CISA SSVC assessment: exploitation active, automatable no, technical impact total.
  • FIRST EPSS (model of 2026-10-21): 27.77% probability of exploitation activity in the next 30 days; percentile 98.

Timeline

  • — CVE record published by facebook
  • — Added to CISA’s Known Exploited Vulnerabilities catalog
  • — CISA remediation deadline for US federal agencies
  • — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vendor and project advisories, patches

  1. source.android.com source.android.com

Vulnerability records

  1. CVE.org record CVE-2025-27363 cve.org
  2. NVD entry CVE-2025-27363 nvd.nist.gov

Government

  1. CISA Known Exploited Vulnerabilities catalog entry cisa.gov

Other references from the CVE record and advisory

  1. facebook.com facebook.com
  2. openwall.com openwall.com
  3. openwall.com openwall.com
  4. openwall.com openwall.com
  5. openwall.com openwall.com
  6. openwall.com openwall.com
  7. openwall.com openwall.com
  8. openwall.com openwall.com
  9. openwall.com openwall.com
  10. openwall.com openwall.com
  11. openwall.com openwall.com
  12. lists.debian.org lists.debian.org
  13. openwall.com openwall.com
  14. openwall.com openwall.com
  15. openwall.com openwall.com

All exploited FreeType vulnerabilities · Today’s Security Digest