Answer in brief
CVE-2026-53504 records a High severity security vulnerability in Thumbor has Regex Denial of Service (ReDoS) in `convolution` filter. The source record does not mark it as known exploited. 1 affected package is mapped in the feed.
Answer in brief
CVE-2026-53504 records a High severity security vulnerability in Thumbor has Regex Denial of Service (ReDoS) in `convolution` filter. The source record does not mark it as known exploited. 1 affected package is mapped in the feed.
Update thumbor to 7.8.0 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanVulnerability describes the vulnerability class recorded for this advisory. The current record does not mark CVE-2026-53504 as known exploited; continue to monitor the source for status changes. The feed includes package mappings that can be checked against lockfiles and deployed manifests.
| Package | Affected range | Fixed version |
|---|---|---|
| thumborpip | <=7.7.7 | 7.8.0 |
Fixed versions are reported by the source feed; confirm compatibility before updating.
Reported by GitHub Security Advisories (ghsa).
CVE-2026-53504 records a High severity security vulnerability in Thumbor has Regex Denial of Service (ReDoS) in `convolution` filter. The source record does not mark it as known exploited. 1 affected package is mapped in the feed.
The source record does not mark it as known exploited.
Check lockfiles and deployed manifests for thumbor.
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL GuardUpdate thumbor to 7.8.0 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanVulnerability describes the vulnerability class recorded for this advisory. The current record does not mark CVE-2026-53504 as known exploited; continue to monitor the source for status changes. The feed includes package mappings that can be checked against lockfiles and deployed manifests.
| Package | Affected range | Fixed version |
|---|---|---|
| thumborpip | <=7.7.7 | 7.8.0 |
Fixed versions are reported by the source feed; confirm compatibility before updating.
Reported by GitHub Security Advisories (ghsa).
CVE-2026-53504 records a High severity security vulnerability in Thumbor has Regex Denial of Service (ReDoS) in `convolution` filter. The source record does not mark it as known exploited. 1 affected package is mapped in the feed.
The source record does not mark it as known exploited.
Check lockfiles and deployed manifests for thumbor.
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL Guard### Summary The regular expression used to parse the `convolution` filter exhibits exponential-time backtracking for certain inputs, enabling a Regular Expression Denial of Service (ReDoS). ### Details The RegExp for `convolution` is defined as `convolution\((?:\s*((?:[-]?[\d]+\.?[\d]*[;])*(?:[-]?[\d]+\.?[\d]*))\s*)(?:,\s*([\d]+)\s*)(?:,\s*([Tt]rue|[Ff]alse|1|0)\s*)?\)`. Within this expression a dangerous subpattern effectively behaves like `(\d+)*,\d+`. ### PoC A filter string containing many repeated values will exhaust `re.match`: - `convolution(-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11)` - http://localhost:8888/unsafe/0x0/smart/filters:convolution(-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11)/x.png The evaluation occurs on https://github.com/thumbor/thumbor/blob/master/thumbor/filters/__init__.py#L189. ### Impact A specially crafted URL will lead to denial of service, as new images won't be processed until `re.match` returns.
### Summary The regular expression used to parse the `convolution` filter exhibits exponential-time backtracking for certain inputs, enabling a Regular Expression Denial of Service (ReDoS). ### Details The RegExp for `convolution` is defined as `convolution\((?:\s*((?:[-]?[\d]+\.?[\d]*[;])*(?:[-]?[\d]+\.?[\d]*))\s*)(?:,\s*([\d]+)\s*)(?:,\s*([Tt]rue|[Ff]alse|1|0)\s*)?\)`. Within this expression a dangerous subpattern effectively behaves like `(\d+)*,\d+`. ### PoC A filter string containing many repeated values will exhaust `re.match`: - `convolution(-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11)` - http://localhost:8888/unsafe/0x0/smart/filters:convolution(-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11;-11)/x.png The evaluation occurs on https://github.com/thumbor/thumbor/blob/master/thumbor/filters/__init__.py#L189. ### Impact A specially crafted URL will lead to denial of service, as new images won't be processed until `re.match` returns.