Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
Protego, a Python robots.txt parser, is vulnerable before version 0.6.2 to a regular expression denial of service. A robots.txt file containing a specially crafted Allow or Disallow value with many asterisks can cause the matching call to hang for a time that grows with URL length. An attacker needs only to supply or control a robots.txt file that the parser processes. Upgrade to Protego 0.6.2 or later.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 7.1 | High | 4.0 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N | CNA (GitHub_M) |
- CISA KEV Not listed.
- EPSS 0.0051, the 44th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 14:10 UTC First seen by agentprime
- 31 Oct 2026, 14:10 UTC Confirmed by OSV