CVE-2020-27511
An issue was discovered in the stripTags and unescapeHTML components in Prototype 1.7.3 version 1...
An issue was discovered in the stripTags and unescapeHTML components in Prototype 1.7.3 where an attacker can cause a Regular Expression Denial of Service (ReDOS) through stripping crafted HTML tags.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
An issue was discovered in the stripTags and unescapeHTML components in Prototype 1.7.3 where an attacker can cause a Regular Expression Denial of Service (ReDOS) through stripping crafted HTML tags.
- Record
CVE-2020-27511- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:N/A:P - Updated
- 2026-11-02
CVE List No score
An issue was discovered in the stripTags and unescapeHTML components in Prototype 1.7.3 where an attacker can cause a Regular Expression Denial of Service (ReDOS) through stripping crafted HTML tags.
- Record
CVE-2020-27511- Updated
- 2026-11-02
EUVDEUVD-2020-20021 No score
An issue was discovered in the stripTags and unescapeHTML components in Prototype 1.7.3 where an attacker can cause a Regular Expression Denial of Service (ReDOS) through stripping crafted HTML tags.
- Record
EUVD-2020-20021- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-6269-grv3-jc94 No score
An issue was discovered in the stripTags and unescapeHTML components in Prototype 1.7.3 version 1...
An issue was discovered in the stripTags and unescapeHTML components in Prototype 1.7.3 version 1.6 and below where an attacker can cause a Regular Expression Denial of Service (ReDOS) through stripping crafted HTML tags.
- Record
GHSA-6269-grv3-jc94- Updated
- 2026-11-02
OSV
An issue was discovered in the stripTags and unescapeHTML components in Prototype 1.7.3 where an attacker can cause a Regular Expression Denial of Service (ReDOS) through stripping crafted HTML tags.
- Record
CVE-2020-27511- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVDEBIAN-CVE-2020-27511
An issue was discovered in the stripTags and unescapeHTML components in Prototype 1.7.3 where an attacker can cause a Regular Expression Denial of Service (ReDOS) through stripping crafted HTML tags.
- Record
DEBIAN-CVE-2020-27511- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2020-27511
An issue was discovered in the stripTags and unescapeHTML components in Prototype 1.7.3 where an attacker can cause a Regular Expression Denial of Service (ReDOS) through stripping crafted HTML tags.
- Record
UBUNTU-CVE-2020-27511- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
prototypejsDebian:12 |
before 1.7.3-1 | 1.7.3-1 |
prototypejsDebian:13 |
before 1.7.3-1 | 1.7.3-1 |
prototypejsDebian:14 |
before 1.7.3-1 | 1.7.3-1 |
prototypejsUbuntu:16.04:LTS |
All versions, plus listed versions 1.7.1-3 |
None known |
prototypejsUbuntu:18.04:LTS |
All versions, plus listed versions 1.7.1-3 |
None known |
prototypejsUbuntu:20.04:LTS |
All versions, plus listed versions 1.7.1-3 |
None known |
prototypejsUbuntu:22.04:LTS |
All versions, plus listed versions 1.7.1-3.1 |
None known |
prototypejsUbuntu:24.04:LTS |
All versions, plus listed versions 1.7.3-1 |
None known |
prototypejsUbuntu:25.10 |
All versions, plus listed versions 1.7.3-2 |
None known |
prototypejsUbuntu:26.10 |
All versions, plus listed versions 1.7.3-2build1 |
None known |
prototypejsUbuntu:26.04:LTS |
All versions, plus listed versions 1.7.3-21.7.3-2build1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-27511 is a high vulnerability (CVSS 7.5) in Prototypejs Prototype, published June 21, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 3.34%, the 88th percentile. Fixed in prototypejs 1.7.3-1.
References
prototypejs.org
github.com/prototypejs/prototype/blob/dee2f7d8611248abce81287e1be4156011953c90/src/prototype/lang/string.js
nvd.nist.gov/vuln/detail/CVE-2020-27511
security-tracker.debian.org/tracker/CVE-2020-27511
ubuntu.com/security/CVE-2020-27511
cve.org/CVERecord?id=CVE-2020-27511