VulnerabilityPublished 16 Jun 2025

CVE-2025-47951: WeblateOrg weblate · Improper Restriction of Excessive Authentication Attempts

Affects WeblateOrg weblateSource CVE Database V5

Not known to be exploited · CVSS 4.9 Medium : upgrade to 5.12 when convenient.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score

4.9Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 18% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 5.12

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

Attack Vector: Network
Attack Complexity: High
Privileges Required: Low
User Interaction: None
Scope: Changed
Confidentiality: Low
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 16 Jun 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade weblateorg/weblate to 5.12.

Affected software

Product	Affected	Fixed in
GitHubweblateorg/weblate`pkg:github/weblateorg/weblate`Other threats	Affected <5.12	Fixed in 5.12

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Immediate Upgrade: Organizations should upgrade Weblate installations to version 5.12 or later, where the vulnerability is patched by implementing rate limiting on the 2FA verification endpoint.
Credential Hygiene: Enforce strong password policies and monitor for credential leaks or reuse to reduce the risk of attackers obtaining valid credentials necessary to exploit this vulnerability.
Enhanced Monitoring: Implement monitoring and alerting for unusual authentication patterns, such as repeated OTP verification attempts from the same IP or account, to detect brute force attempts early.
Network Controls: Restrict access to Weblate administrative and authentication endpoints via IP whitelisting or VPNs where feasible, limiting exposure to potential attackers.
Multi-Factor Authentication Alternatives: Consider deploying additional or alternative second factor methods that may be less susceptible to automated guessing, such as hardware tokens or push-based authentication, if supported.
Incident Response Preparedness: Develop and test incident response plans that include steps for handling suspected account compromises in Weblate, including forced password resets and session invalidation.
Application Layer Protections: If upgrading is delayed, implement external rate limiting or web application firewall (WAF) rules to throttle requests to the 2FA endpoint, mitigating brute force attempts at the network perimeter.

Description

Weblate is a web based localization tool. Prior to version 5.12, the verification of the second factor was not subject to rate limiting. The absence of rate limiting on the second factor endpoint allows an attacker with valid credentials to automate OTP guessing. This issue has been patched in version 5.12.

Impact

For European organizations using Weblate versions prior to 5.12, this vulnerability poses a risk of unauthorized account access despite the presence of two-factor authentication. Attackers who have compromised or obtained valid credentials can bypass the second factor by brute forcing OTPs without being rate limited, potentially leading to account takeover. This can result in unauthorized modification or leakage of sensitive localization data, which may include proprietary software strings, internal documentation, or customer-facing content. Such compromises could damage the organization's reputation, lead to intellectual property theft, or introduce malicious content into localized software builds. The impact is particularly significant for organizations in sectors with strict data protection requirements, such as finance, healthcare, and government, where integrity and confidentiality of localized content are critical. Additionally, since Weblate is often integrated into CI/CD pipelines for software releases, compromised accounts could be leveraged to inject malicious code or disrupt release processes, indirectly affecting availability and trustworthiness of software products. Although no availability impact is directly associated with this vulnerability, the broader scope change means that attackers might pivot to other systems or escalate privileges after bypassing 2FA. The medium severity rating suggests that while the vulnerability is not trivial to exploit (due to the need for valid credentials and high attack complexity), the potential consequences warrant attention, especially in environments with high-value localization data or regulatory compliance obligations.

CWE-307Improper Restriction of Excessive Authentication Attempts (opens in a new tab)
Base weaknessOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
The product does not implement sufficient measures to prevent multiple failed authentication attempts within a short time frame.
Architecture and Design
Common protection mechanisms include: Disconnecting the user after a small number of failed attempts; Implementing a timeout; Locking out a targeted account; Requiring a computational task on the user's part.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
OWASP Cheat Sheets
Authentication (opens in a new tab)
Transport Layer Protection (opens in a new tab)
TLS Cipher String (opens in a new tab)
OWASP ASVS 4.0.3
V2.2.1 (opens in a new tab)
V2.8.5 (opens in a new tab)
V2.8.4 (opens in a new tab)
Attack patterns
Dictionary-based Password Attack (opens in a new tab)
Password Brute Forcing (opens in a new tab)
Password Spraying (opens in a new tab)
Credential Stuffing (opens in a new tab)
Use of Known Kerberos Credentials (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 16 Jun 2025, 21:19 UTC

WeaknessesCWE-307

Technical details

References

Community reviews

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