Skip to content
Fencer Vulns
medium 6.5

CVE-2023-26047 json

teler-waf contains detection rule bypass via entities payload

published 2023-03-01 3 y ago modified 2026-09-10 1 mo ago also GHSA-p2pf-g8cq-3gq5 , GO-2023-1600 , EUVD-2023-1062

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 44%
public exploits
0
none known

Summary

teler-waf is a Go HTTP middleware that provides teler IDS functionality to protect against web-based attacks. In teler-waf prior to version v0.2.0 is vulnerable to a bypass attack when a specific case-sensitive hex entities payload with special characters such as CR/LF and horizontal tab is used. This vulnerability allows an attacker to execute arbitrary JavaScript code on the victim's browser and compromise the security of the web application. An attacker can exploit this vulnerability to bypass common web attack threat rules in teler-waf and launch cross-site scripting (XSS) attacks. The attacker can execute arbitrary JavaScript code on the victim's browser and steal sensitive information, such as login credentials and session tokens, or take control of the victim's browser and perform malicious actions. This issue has been patched in version 0.2.0.

Patch / fix

  • go github.com/kitabisa/teler-waf 0.2.0
  • kitabisa teler-waf 0.2.0

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
20 mo ago

Exploit prediction

0.52% chance of exploitation in the next 30 days, higher than 44% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
NVD 3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
GitHub 3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Affected packages

ecosystem package affected fixed in
go github.com/kitabisa/teler-waf
<0.2.0
0.2.0

Affected products

  • kitabisa teler-waf

Classification

Weakness
  • CWE-80 Improper Neutralization of Script-Related HTML Tags in a Web Page
  • CWE-692 Incomplete Denylist to Cross-Site Scripting
  • CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.