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CVE-2023-49991

16
FAUCET Score

CVE-2023-49991 describes a Stack Buffer Underflow vulnerability in Espeak-ng version 1.52-dev, specifically within the CountVowelPosition function in synthdata.c. This vulnerability carries a CVSS score of 5.3 (Medium), indicating a local attack vector with low complexity, requiring user interaction, and potentially leading to limited impact on confidentiality, integrity, and availability. There is currently no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion or media coverage surrounding this CVE.

Impacted Technologies

VendorProductVersion(s)CPE
1.52CPE matchmatch criteria
cpe:2.3:a:espeak-ng:espeak-ng:1.52:dev:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

5.3MEDIUM

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L

Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality Impact
LOW
Integrity Impact
LOW
Availability Impact
LOW
Exploitability Score
1.8
Impact Score
3.4
CvssVersion
3.1

Exploit Intelligence

EPSS Score
0.37%
Probability of exploitation in next 30 days
EPSS Percentile
29.9%
Percentile rank of EPSS score among Peer Group
As of 2026-07-26
Model: v2026.06.15
This CVE's current EPSS score of 0.0037 is in the 37th percentile among its peer group of 5,758 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.0 Bluesky, 0.0 Mastodon, and 0.1 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (7)

microsoftpatch availablevia msrc
Product: 18420-17084Fixed in: 1.52.0-1
microsoftpatch availablevia msrc
Product: 18421-17084Fixed in: 1.52.0-1
microsoftpatch availablevia msrc
Product: azl3 espeak-ng 1.51.1-1 on Azure Linux 3.0Fixed in: 1.52.0-1
microsoftpatch availablevia msrc
Product: azl3 espeak-ng 1.52.0-1 on Azure Linux 3.0Fixed in: 1.52.0-1
github_advisoryvendor investigatingvia nvd_reference
View patch
redhatend of lifevia redhat_api
Product: Red Hat Enterprise Linux 8Fixed in: espeak-ng
redhatend of lifevia redhat_api
Product: Red Hat Enterprise Linux 9Fixed in: espeak-ng

Vendor Advisories (2)

microsoft2023-Dec/CVE-2023-49991Moderate

Espeak-ng 1.52-dev was discovered to contain a Stack Buffer Underflow via the function CountVowelPosition at synthdata.c.

Dec 12, 2023
redhatCVE-2023-49991Moderate

espeak-ng: buffer underflow in CountVowelPosition function at synthdata.c

Dec 12, 2023

References

lists.debian.org / debian-lts-announce/2025/05/msg00050.html
lists.fedoraproject.org / archives/list/[email protected]/message/2PZEBWPNKPAYJMIM3AS2RP3FL6FX3HS4
lists.fedoraproject.org / archives/list/[email protected]/message/Z5WW6RKHRWLEMCKCQ6UZCXWC5J7UWMUQ
github.com / espeak-ng/espeak-ng/issues/1825
ExploitIssue TrackingVendor Advisory
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/2PZEBWPNKPAYJMIM3AS2RP3FL6FX3HS4
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/Z5WW6RKHRWLEMCKCQ6UZCXWC5J7UWMUQ